WorldWideScience

Sample records for twin lobed farfield

  1. Multiple lobes in the far-field distribution of terahertz quantum-cascade lasers due to self-interference

    Energy Technology Data Exchange (ETDEWEB)

    Röben, B., E-mail: roeben@pdi-berlin.de; Wienold, M.; Schrottke, L.; Grahn, H. T. [Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5–7, 10117 Berlin (Germany)

    2016-06-15

    The far-field distribution of the emission intensity of terahertz (THz) quantum-cascade lasers (QCLs) frequently exhibits multiple lobes instead of a single-lobed Gaussian distribution. We show that such multiple lobes can result from self-interference related to the typically large beam divergence of THz QCLs and the presence of an inevitable cryogenic operation environment including optical windows. We develop a quantitative model to reproduce the multiple lobes. We also demonstrate how a single-lobed far-field distribution can be achieved.

  2. Sco X-1 The Evolution and Nature of the Twin Compact Radio Lobes

    CERN Document Server

    Fomalont, E B; Bradshaw, C F

    2001-01-01

    The radio components associated with the LMXB Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over four years, including a 56-hour continuous VLBI observation in 1999 June. We often detected one strong and one weak compact radio component, moving in opposite directions from the radio core. We suggest that the moving components are radio lobes generated by the disruption of energy flow in a twin-beam from the binary system. The average lifetime of a lobe-pair, the space motion of the lobes and the measured energy flow in the beam are discussed in Astro-ph/0104325. The lobe has a flux density that is variable over a time-scale of one hour, a measured minimum size of 1 mas (2.8 au), and is extended perpendicular to its motion. This short electron radiative lifetime may be caused by synchrotron losses if the lobe magnetic field is 300 G, or by adiabatic expansion of the electrons as soon as they are produced at the working surface. The lobes also show periods of slow expansion and a ste...

  3. Achieving single-lobed far-field patterns of broad area laser diode with external cavity feedback

    Institute of Scientific and Technical Information of China (English)

    Jianhong Ge(葛剑虹); Jun Chen(陈军); Andreas Hermerschmidt; H.J.Eichler

    2003-01-01

    We demonstrate a technique for single transverse mode operation of high-power broad area laser diode(BAL). In the experiment, the HR mirror is used as an external cavity mirror and the grating is used as a wavelength selective component. By tiling the HR mirror and the grating, the number of transverse modes oscillating in the cavity can be limited and the spectral bandwidth of the laser diode can be reduced. A single-lobed near diffraction-limited laser beam with the beam divergence (FWHM) of 0.43°, the spectral line-width of 0.7 nm and the output power of 350 mW are obtained. With the feedback, the power density of the output laser beam is increased 6 times in comparison with the free running.

  4. Scorpius X-1: The Evolution and Nature of the Twin Compact Radio Lobes

    Science.gov (United States)

    Fomalont, E. B.; Geldzahler, B. J.; Bradshaw, C. F.

    2001-09-01

    The motion and variability of the radio components in the low-mass X-ray binary system Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over 4 yr, including a 56 hr continuous VLBI observation in 1999 June. We detect one strong and one weak compact radio component, moving in opposite directions from the radio core. Their relative motion and flux densities are consistent with relativistic effects, from which we derive an average component speed of v/c=0.45+/-0.03 at an angle of 44deg+/-6deg to the line of sight. This inclination of the binary orbit suggests a mass of the secondary star that is less than 0.9 Msolar, assuming a neutron star mass of 1.4 Msolar. We suggest that the two moving radio components consist of ultrarelativistic plasma that is produced at a working surface where the energy in dual-opposing beams disrupt. The radio lobe advance velocity is constant over many hours, but differs among lobe-pairs: 0.32c, 0.46c, 0.48c, and 0.57c. A lobe-pair lifetime is less than 2 days, with a new pair formed near the core within a day. The lobe flux has flux density that is variable over a timescale of 1 hr, has a measured minimum size of 1 mas (4×108 km), and is extended perpendicular to its motion. This timescale and size are consistent with an electron radiative lifetime of less than 1 hr. Such a short lifetime can be caused by synchrotron losses if the lobe magnetic field is 300 G or by adiabatic expansion of the electrons as soon as they are produced at the working surface. The lobes also show periods of slow expansion and a steepening radio spectrum. Two of the core flares are correlated with the lobe flares under the assumption that the flares are produced by an energy burst traveling down the beams with a speed greater than 0.95. The radio morphology for Sco X-1 differs from most other Galactic jet sources. Possible reasons for the morphology difference are that Sco X-1 is associated with a neutron star, it is a persistent X

  5. Pareto optimality between width of central lobe and peak sidelobe intensity in the far-field pattern of lossless phase-only filters for enhancement of transverse resolution.

    Science.gov (United States)

    Mukhopadhyay, Somparna; Hazra, Lakshminarayan

    2015-11-01

    Resolution capability of an optical imaging system can be enhanced by reducing the width of the central lobe of the point spread function. Attempts to achieve the same by pupil plane filtering give rise to a concomitant increase in sidelobe intensity. The mutual exclusivity between these two objectives may be considered as a multiobjective optimization problem that does not have a unique solution; rather, a class of trade-off solutions called Pareto optimal solutions may be generated. Pareto fronts in the synthesis of lossless phase-only pupil plane filters to achieve superresolution with prespecified lower limits for the Strehl ratio are explored by using the particle swarm optimization technique.

  6. Influence of turbulent atmosphere on the far-field coherent combined beam quality

    Institute of Scientific and Technical Information of China (English)

    Pu Zhou; Zejin Liu; Xiaojun Xu; Xiaolin Wang; Xiao Li; Zilun Chen

    2008-01-01

    Propagation of coherent combined laser beams in turbulent atmosphere is numerically studied based on the extended Huygens-Fresnel principle. By choosing beam propagation factor (BPF) and beam quality factor (BQ) to characterize the far-field irradiance distribution properties, the influence of turbulence on far-field coherent combined beam quality is studied in detail. The investigation reveals that with the coherence length decreasing, the irradiance distribution pattern evolves from typical non-Gaussian shape with multiple side-lobes into Gaussian shape which is seen in the incoherent combining case. In weak turbulent atmosphere, the far-field beam quality suffers less when the 1aser array gets more compact and operates at a longer wavelength. In strong turbulent atmosphere, the far-field beam quality degrades into the incoherent combining case without any relationship with the fill factor and laser wavelength.

  7. An improved schlieren method for measurement and automatic reconstruction of the far-field focal spot

    Science.gov (United States)

    Wang, Zhengzhou; Hu, Bingliang; Yin, Qinye

    2017-01-01

    The schlieren method of measuring far-field focal spots offers many advantages at the Shenguang III laser facility such as low cost and automatic laser-path collimation. However, current methods of far-field focal spot measurement often suffer from low precision and efficiency when the final focal spot is merged manually, thereby reducing the accuracy of reconstruction. In this paper, we introduce an improved schlieren method to construct the high dynamic-range image of far-field focal spots and improve the reconstruction accuracy and efficiency. First, a detection method based on weak light beam sampling and magnification imaging was designed; images of the main and side lobes of the focused laser irradiance in the far field were obtained using two scientific CCD cameras. Second, using a self-correlation template matching algorithm, a circle the same size as the schlieren ball was dug from the main lobe cutting image and used to change the relative region of the main lobe cutting image within a 100×100 pixel region. The position that had the largest correlation coefficient between the side lobe cutting image and the main lobe cutting image when a circle was dug was identified as the best matching point. Finally, the least squares method was used to fit the center of the side lobe schlieren small ball, and the error was less than 1 pixel. The experimental results show that this method enables the accurate, high-dynamic-range measurement of a far-field focal spot and automatic image reconstruction. Because the best matching point is obtained through image processing rather than traditional reconstruction methods based on manual splicing, this method is less sensitive to the efficiency of focal-spot reconstruction and thus offers better experimental precision. PMID:28207758

  8. Conjoined Twins

    Science.gov (United States)

    ... sites of conjoined twins. Abdomen. Omphalopagus (om-fuh-LOP-uh-gus) twins are joined near the bellybutton. ... brain tissue. Head and chest. Cephalopagus (sef-uh-LOP-uh-gus) twins are joined at the face ...

  9. ACARDIAC TWIN

    OpenAIRE

    Vinayachandran; Jyothi,; Bindu; Umadevi

    2014-01-01

    Acardiac twin is a very rare complication occurring in monozygotic twins in which one fetus develops normally (pump twin) and the other (recipient twin) demonstrate cardiac non development and othe r anomalies. This may represent an extreme form of TTTS, also referred to as TRAP sequence. 1,2,

  10. Twin births

    DEFF Research Database (Denmark)

    Hoffmann, Elise; Oldenburg, Anna; Rode, Line;

    2012-01-01

    To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery.......To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery....

  11. Far-field environment working group summary

    Energy Technology Data Exchange (ETDEWEB)

    Pearcy, E.C. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States); Cady, R.E. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This article is a summary of the proceedings of a group discussion which took place at the Workshop on the Role of Natural Analogs in Geologic Disposal of High-Level Nuclear Waste in San Antonio, Texas on July 22-25, 1991. The working group concentrated on the subject of the potential impacts of underground disposal of high-level radioactive wastes on the far-field environment.

  12. Twin pregnancy

    DEFF Research Database (Denmark)

    Sperling, Lene; Tabor, A

    2001-01-01

    Determination of chorionicity is one of the most important issues in the management of twin pregnancy. Modern ultrasound equipment has made it possible to accurately assess placentation already in the first trimester with the lambda sign. With regard to prenatal diagnosis, it is important to know...... for clinicians caring for twin pregnancies....

  13. Twin Baryogenesis

    CERN Document Server

    Farina, Marco; Shin, Chang Sub

    2016-01-01

    In the context of Twin Higgs models, we study a simple mechanism that simultaneously generates asymmetries in the dark and visible sector through the out-of-equilibrium decay of a TeV scale particle charged under a combination of baryon and twin baryon number. We predict the dark matter to be a 5 GeV twin baryon, which is easy to achieve because of the similarity between the two confinement scales. Dark matter is metastable and can decay to three quarks, yielding indirect detection signatures. The mechanism requires the introduction of a new colored particle, typically within the reach of the LHC, of which we study the rich collider phenomenology, including prompt and displaced dijets, multi-jets, monojets and monotops.

  14. Maximum twin shear stress factor criterion for sliding mode fracture initiation

    Institute of Scientific and Technical Information of China (English)

    黎振兹; 李慧剑; 黎晓峰; 周洪彬; 郝圣旺

    2002-01-01

    Previous researches on the mixed mode fracture initiation criteria were mostly focused on opening mode fracture. In this study, the authors proposed a new criterion for mixed mode sliding fracture initiation, which is the maximum twin shear stress factor criterion. The authors studied a finite width plate with central slant crack, subject to a far-field uniform uniaxial tensile or compressive stress.

  15. Far-field characteristics of the square grooved-dielectric lens antenna for the terahertz band.

    Science.gov (United States)

    Pan, Wu; Zeng, Wei

    2016-09-10

    In order to improve the gain and directionality of a terahertz antenna, a square grooved-dielectric lens antenna based on a Fresnel zone plate is proposed. First, a diagonal horn, which is adopted as the primary feed antenna, is designed. Then, the far-field characteristics of the lens antenna are studied by using Fresnel-Kirchhoff diffraction theory and the paraxial approximation. The effects of the full-wave period, the focus diameter ratio, the subregion, and the dielectric substrate thickness on radiation characteristics are studied. The experimental results show that the proposed lens antenna has axisymmetric radiation patterns. The gain is over 26.1 dB, and the 3 dB main lobe beam width is lower than 5.6° across the operation band. The proposed lens antenna is qualified for applications in terahertz wireless communication systems.

  16. Steering far-field spin-dependent splitting of light by inhomogeneous anisotropic media

    CERN Document Server

    Ling, Xiaohui; Luo, Hailu; Wen, Shuangchun

    2012-01-01

    An inhomogeneous anisotropic medium with specific structure geometry can apply tunable spin-dependent geometrical phase to the light passing through the medium, and thus can be used to steer the spin-dependent splitting (SDS) of light. In this paper, we exemplify this inference by the $q$-plate, an inhomogeneous anisotropic medium. It is demonstrated that when a linearly polarized light beam normally passes through a $q$-plate, $k$-space SDS first occurs, and then the real-space SDS in the far-field focal plane of a converging lens is distinguishable. Interestingly, the SDS, described by the normalized Stokes parameter $S_3$, shows a multi-lobe and rotatable splitting pattern with rotational symmetry. Further, by tailoring the structure geometry of $q$-plate or/and incident polarization angle of light, the lobe number and the rotation angle both are tunable. Our result suggests that the $q$-plate can serve as potential devices for manipulating the photon spin states and enable applications such as in nano-opt...

  17. Neocortical Temporal Lobe Epilepsy

    Science.gov (United States)

    Bercovici, Eduard; Kumar, Balagobal Santosh; Mirsattari, Seyed M.

    2012-01-01

    Complex partial seizures (CPSs) can present with various semiologies, while mesial temporal lobe epilepsy (mTLE) is a well-recognized cause of CPS, neocortical temporal lobe epilepsy (nTLE) albeit being less common is increasingly recognized as separate disease entity. Differentiating the two remains a challenge for epileptologists as many symptoms overlap due to reciprocal connections between the neocortical and the mesial temporal regions. Various studies have attempted to correctly localize the seizure focus in nTLE as patients with this disorder may benefit from surgery. While earlier work predicted poor outcomes in this population, recent work challenges those ideas yielding good outcomes in part due to better localization using improved anatomical and functional techniques. This paper provides a comprehensive review of the diagnostic workup, particularly the application of recent advances in electroencephalography and functional brain imaging, in neocortical temporal lobe epilepsy. PMID:22953057

  18. The Qingdao Twin Registry

    DEFF Research Database (Denmark)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng;

    2013-01-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants...... of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes...

  19. Twin Jet

    Science.gov (United States)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  20. Spectrally resolved far-fields of terahertz quantum cascade lasers

    CERN Document Server

    Brandstetter, Martin; Krall, Michael; Kainz, Martin A; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron M; Strasser, Gottfried; Unterrainer, Karl

    2016-01-01

    We demonstrate a convenient and fast method to measure the spectrally resolved far-fields of multimode terahertz quantum cascade lasers by combining a microbolometer focal plane array with an FTIR spectrometer. Far-fields of fundamental TM0 and higher lateral order TM1 modes of multimode Fabry-P\\'erot type lasers have been distinguished, which very well fit to the results obtained by a 3D finite-element simulation. Furthermore, multimode random laser cavities have been investigated, analyzing the contribution of each single laser mode to the total far-field. The presented method is thus an important tool to gain in-depth knowledge of the emission properties of multimode laser cavities at terahertz frequencies, which become increasingly important for future sensing applications.

  1. Deformation twinning in monazite

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R.S.; Marshall, D.B

    2003-10-20

    Polycrystalline monazite (LaPO{sub 4}) was deformed at room temperature by a spherical indenter. Deformation twins were identified by TEM in 70 grains. Five twin planes were found: (100) was by far the most common; (001) and (120) were less common; (122-bar)was rare, and kinks in (120) twins were identified as irrational '(483)' twin planes. The twinning modes on these planes were inferred from the expression of twinning shear at free surfaces, predictions of classical deformation twinning theory, and various considerations of twin morphology and crystal structure. Atomic shuffle calculations that allow formation of either a glide plane or a mirror plane at the twin interface were used to analyze twin modes. The inferred twin modes all have small atomic shuffles. For (001) twins, the smallest shuffles were obtained with a glide plane at the interface, with displacement vector R=((1)/(2))[010]. The results do not uniquely define a twin mode on (100), leaving open the possibility of more than one mode operating on this plane. Factors that may determine the operative deformation twinning modes are discussed. Crystal structure considerations suggest that the relative abundance of twinning modes may correlate with low shear modulus on the twin plane in the direction of twinning shear, and with a possible low-energy interface structure consisting of a layer of xenotime of one half-unit-cell thickness that could form at (100) and (001) twins. The three most common twins have low strains to low {sigma} coincidence site lattices (CSLs)

  2. The Norwegian Twin Registry.

    Science.gov (United States)

    Nilsen, Thomas S; Brandt, Ingunn; Magnus, Per; Harris, Jennifer R

    2012-12-01

    Norway has a long-standing tradition in twin research, but the data collected in several population-based twin studies were not coordinated centrally or easily accessible to the scientific community. In 2009, the Norwegian Twin Registry was established at the Norwegian Institute of Public Health (NIPH) in Oslo with the purpose of creating a single research resource for Norwegian twin data. As of today, the Norwegian Twin Registry contains 47,989 twins covering birth years 1895-1960 and 1967-1979; 31,440 of these twins consented to participate in health-related research. In addition, DNA from approximately 4,800 of the twins is banked at the NIPH biobank and new studies are continually adding new data to the registry. The value of the Norwegian twin data is greatly enhanced by the linkage opportunities offered by Norway's many nationwide registries, spanning a broad array of medical, demographic, and socioeconomic information.

  3. Natural analogs for far-field environment/hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Hoxie, D.T. [Geological Survey, Denver, CO (United States)

    1995-09-01

    This paper discusses the applicability of natural-analog studies to characterize far-field conditions in the vicinity of geologic repository systems for the disposal of high-level radioactive wastes. Conditions in the far field are determined by the natural state and evolution of the repository geosphere and its environment.

  4. RECONSTRUCTION OF SCATTERED FIELD FROM FAR-FIELD BY REGULARIZATION

    Institute of Scientific and Technical Information of China (English)

    Ji-jun Liu; Jin Cheng; G. Nakamura

    2004-01-01

    In this paper, we consider an inverse scattering problem for an obstacle D(∪)R2 with Robin boundary condition. By applying the point source, we give a regularizing method to recover the scattered field from the far-field pattern. Numerical implementations are also presented.

  5. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A;

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  6. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  7. Monochorionic twin pregnancies

    NARCIS (Netherlands)

    Hack, K.E.A.

    2008-01-01

    Following widespread application of assisted reproductive technology modalities and the increased age of motherhood, the incidence of twin gestations has increased markedly. Twins are either monozygotic or dizygotic. Dizygotic (i.e. fraternal) twins result from the fertilization of two different egg

  8. Hypersexuality after Temporal Lobe Resection.

    Science.gov (United States)

    Baird, Amee D.; Wilson, Sarah J.; Bladin, Peter F.; Saling, Michael M.; Reutens, David C.

    2002-04-01

    Hypersexuality has occasionally been reported in patients with temporal lobe epilepsy following temporal lobe resection. The mechanism underlying this phenomenon is poorly understood. We describe seven patients who spontaneously reported dramatic postoperative changes in sexual behavior after unilateral temporal lobe resection. Five of the seven patients showed evidence of bilateral temporal lobe abnormalities. All of the patients had significant difficulties with postoperative psychosocial adjustment that preceded the onset of hypersexuality. Five of the patients were completely seizure-free and one reported postoperative auras. Recurrent complex partial seizures occurred at a reduced frequency in one patient after 6 months. In this patient, the period of seizure freedom did not directly correlate with the period of hypersexuality. These cases suggest that hypersexuality following unilateral temporal lobe resection is more likely to occur in the presence of psychosocial difficulties and contralateral temporal lobe abnormalities. Neurophysiological processes associated with seizure cessation alone do not appear to account for postoperative hypersexuality.

  9. Far-Field Microscopy of Sparse Subwavelength Objects

    CERN Document Server

    Szameit, A; Dana, H; Steiner, S; Gazit, S; Cohen-Hyams, T; Bullkich, E; Cohen, O; Eldar, Y C; Shoham, S; Kley, E B; Segev, M

    2010-01-01

    We present the experimental reconstruction of sub-wavelength features from the far-field of sparse optical objects. We show that it is sufficient to know that the object is sparse, and only that, and recover 100 nm features with the resolution of 30 nm, for an illuminating wavelength of =532 nm. Our technique works in real-time, requires no scanning, and can be implemented in all existing microscopes - optical and non-optical.

  10. Parietal lobe epilepsy.

    Science.gov (United States)

    Salanova, Vicenta

    2012-10-01

    Patients with parietal lobe epilepsy (PLE) exhibit an electroclinical epilepsy syndrome that is rarely seen even at large epilepsy centers. Clinically, most patients with PLE exhibit a somatosensory aura that may include painful dysesthesias, though vertigo, aphasia, disturbances of one's body image also occur, when ictal propagation occurs from the parietal lobe to the supplementary motor area, hypermotor manifestations are noted. When temporolimbic propagation occurs, complex visual or auditory hallucinations and automatisms may appear. Scalp electroencephalogram (EEG) is often nonlocalizing. Ictal EEG is rarely localizing in PLE, and invasive EEG is often required for definitive localization and functional mapping. Recent advances in clinical neurophysiology during the evaluation of patients with refractory partial epilepsy include Ictal magnetic source imaging (MSI). Combined EEG and functional magnetic resonance imaging (EEG-fMRI) may be useful for patients with PLE to refine the localization in patients undergoing a presurgical evaluation. High-frequency oscillations (HFOs) are more concentrated inside the seizure onset zone (SOZ), indicating that they may be used as interictal scalp EEG biomarker for the SOZ. When medical therapy fails, resective epilepsy surgery can result in seizure freedom or significant reduction especially when a lesion is present.

  11. Topological magnetoelectric effects in microwave far-field radiation

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, M.; Kamenetskii, E. O.; Shavit, R. [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

    2016-07-21

    Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.

  12. Hybrid multilevel plane wave based near-field far-field transformation utilising combined near- and far-field translations

    Directory of Open Access Journals (Sweden)

    C. H. Schmidt

    2009-05-01

    Full Text Available The radiation of large antennas and those operating at low frequencies can be determined efficiently by near-field measurement techniques and a subsequent near-field far-field transformation. Various approaches and algorithms have been researched but for electrically large antennas and irregular measurement contours advanced algorithms with low computation complexity are required. In this paper an algorithm employing plane waves as equivalent sources and utilising efficient diagonal translation operators is presented. The efficiency is further enhanced using simple far-field translations in combination with the expensive near-field translations. In this way a low complexity near-field transformation is achieved, which works for arbitrary sample point distributions and incorporates a full probe correction without increasing the complexity.

  13. 3D CFD analysis of a twin screw expander

    OpenAIRE

    Kovacevic, A.; S Rane

    2013-01-01

    Twin screw machines can be used as expanders for variety of applications. This paper describes how the performance of an oil free twin screw air expander of 3/5 lobe configuration was estimated by use of full 3D Computational Fluid Dynamics (CFD) applying a procedure similar to that used for screw compressors. The grid generator SCORG© was employed for pre-processing of the moving domains between the rotors while the stationary grids for the ports were derived from a commercial grid generator...

  14. Temporal lobe epilepsy semiology.

    Science.gov (United States)

    Blair, Robert D G

    2012-01-01

    Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE) is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures) is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE). Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone.

  15. Malaysian Twin Registry.

    Science.gov (United States)

    Jahanfar, Shayesteh; Jaffar, Sharifah Halimah

    2013-02-01

    The National Malaysian Twin Registry was established in Royal College of Medicine, Perak, University Kuala Lumpur (UniKL) in June 2008 through a grant provided by UniKL. The general objective is to facilitate scientific research involving participation of twins and their family members in order to answer questions of health and wellbeing relevant to Malaysians. Recruitment is done via mass media, poster, and pamphlets. We now have 266 adult and 204 children twins registered. Several research projects including reproductive health study of twins and the role of co-bedding on growth and development of children are carried out. Registry holds annual activities for twins and seeks to provide health-related information for twins. We seek international collaboration.

  16. Perinatal hepatic infarction in twin-twin transfusion.

    LENUS (Irish Health Repository)

    O'Sullivan, M J

    2012-02-03

    We report a case of a twin pregnancy which was complicated by a twin-twin transfusion in which the recipient twin was noted to have an intra-abdominal echogenic mass. This twin died at two days of age of hepatic infarction. The donor twin was healthy at birth, at thirty weeks\\' gestation, and did not have any subsequent problems. Fetal intra-abdominal echogenicity may be a marker of hepatic infarction.

  17. The Brazilian Twin Registry.

    Science.gov (United States)

    Ferreira, Paulo H; Oliveira, Vinicius C; Junqueira, Daniela R; Cisneros, Lígia C; Ferreira, Lucas C; Murphy, Kate; Ordoñana, Juan R; Hopper, John L; Teixeira-Salmela, Luci F

    2016-12-01

    The Brazilian Twin Registry (BTR) was established in 2013 and has impelled twin research in South America. The main aim of the initiative was to create a resource that would be accessible to the Brazilian scientific community as well as international researchers interested in the investigation of the contribution of genetic and environmental factors in the development of common diseases, phenotypes, and human behavior traits. The BTR is a joint effort between academic and governmental institutions from Brazil and Australia. The collaboration includes the Federal University of Minas Gerais (UFMG) in Brazil, the University of Sydney and University of Melbourne in Australia, the Australian Twin Registry, as well as the research foundations CNPq and CAPES in Brazil. The BTR is a member of the International Network of Twin Registries. Recruitment strategies used to register twins have been through participation in a longitudinal study investigating genetic and environmental factors for low back pain occurrence, and from a variety of sources including media campaigns and social networking. Currently, 291 twins are registered in the BTR, with data on demographics, zygosity, anthropometrics, and health history having been collected from 151 twins using a standardized self-reported questionnaire. Future BTR plans include the registration of thousands of Brazilian twins identified from different sources and collaborate nationally and internationally with other research groups interested on twin studies.

  18. Delivery in Twin Gestation

    Directory of Open Access Journals (Sweden)

    Mark T. Peters

    1995-01-01

    Full Text Available Objective: The objective of this study was to determine whether prophylactic treatment with oral broad-spectrum antimicrobial therapy improves pregnancy outcomes in twin gestations.

  19. Optimization of Fixed Microphone Array in High Speed Train Noises Identification Based on Far-Field Acoustic Holography

    Directory of Open Access Journals (Sweden)

    Rujia Wang

    2017-01-01

    Full Text Available Acoustical holography has been widely applied for noise sources location and sound field measurement. Performance of the microphones array directly determines the sound source recognition method. Therefore, research is very important to the performance of the microphone array, its array of applications, selection, and how to design instructive. In this paper, based on acoustic holography moving sound source identification theory, the optimization method is applied in design of the microphone array, we select the main side lobe ratio and the main lobe area as the optimization objective function and then put the optimization method use in the sound source identification based on holography, and finally we designed this paper to optimize microphone array and compare the original array of equally spaced array with optimization results; by analyzing the optimization results and objectives, we get that the array can be achieved which is optimized not only to reduce the microphone but also to change objective function results, while improving the far-field acoustic holography resolving effect. Validation experiments have showed that the optimization method is suitable for high speed trains sound source identification microphone array optimization.

  20. PORTAL SUPPLY TO CAUDATE LOBE AND QUADRATE LOBE OF LIVER

    Directory of Open Access Journals (Sweden)

    Maheswari

    2015-09-01

    Full Text Available The precise knowledge of intra hepatic branching pattern of portal vein to caudate lobe and quadrate lobe is important for Gastroenterologist during hepatic segmental and subsegmental resection. The study was done in 47 adult human liver specimens. In this study methods like Manual dissection and Contrast study were used. During this study the portal branches to caudate l obe, Quadrate lobe and accessory branches to segment IV in addition to its branches were observed. The results were compared with previous studies

  1. Far-field super-resolution imaging of resonant multiples

    KAUST Repository

    Guo, Bowen

    2016-05-20

    We demonstrate for the first time that seismic resonant multiples, usually considered as noise, can be used for super-resolution imaging in the far-field region of sources and receivers. Tests with both synthetic data and field data show that resonant multiples can image reflector boundaries with resolutions more than twice the classical resolution limit. Resolution increases with the order of the resonant multiples. This procedure has important applications in earthquake and exploration seismology, radar, sonar, LIDAR (light detection and ranging), and ultrasound imaging, where the multiples can be used to make high-resolution images.

  2. Massive Temporal Lobe Cholesteatoma

    Directory of Open Access Journals (Sweden)

    Pasan Waidyasekara

    2015-01-01

    Full Text Available Introduction. Intracranial extension of cholesteatoma is rare. This may occur de novo or recur some time later either contiguous with or separate to the site of the original cholesteatoma. Presentation of Case. A 63-year-old female presented to a tertiary referral hospital with a fluctuating level of consciousness, fever, headache, and right-sided otorrhoea, progressing over several days. Her past medical history included surgery for right ear cholesteatoma and drainage of intracranial abscess 23 years priorly. There had been no relevant symptoms in the interim until 6 weeks prior to this presentation. Imaging demonstrated a large right temporal lobe mass contiguous with the middle ear and mastoid cavity with features consistent with cholesteatoma. The patient underwent a combined transmastoid/middle fossa approach for removal of the cholesteatoma and repair of the tegmen dehiscence. The patient made an uneventful recovery and remains well over 12 months later. Conclusion. This case presentation details a large intracranial cholesteatoma which had extended through a tegmen tympani dehiscence from recurrent right ear cholesteatoma treated by modified radical mastoidectomy over two decades priorly. There was a completely asymptomatic progression of disease until several weeks prior to this presentation.

  3. Temporal Lobe Epilepsy Semiology

    Directory of Open Access Journals (Sweden)

    Robert D. G. Blair

    2012-01-01

    Full Text Available Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE. Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone.

  4. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak Syst

  5. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Ohm Kyvik, Kirsten; Vilstrup Holm, Niels

    2011-01-01

    Introduction: The Danish Twin Registry is a unique source for studies of genetic, familial and environmental factors on life events, health conditions and diseases. Content: More than 85,000 twin pairs born 1870-2008 in Denmark. Validity and coverage: Four main ascertainment methods have been emp...

  6. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak

  7. Occipital lobe infarctions are different

    OpenAIRE

    Naess, Halvor; Waje-Andreassen, Ulrikke; Thomassen, Lars

    2007-01-01

    Objectives We hypothesized that occipital lobe infarctions differ from infarctions in other locations as to etiology, risk factors and prognosis among young adults. Methods Location, etiology, risk factors and long-term outcome were evaluated among all young adults 15–49 years suffering from cerebral infarction in Hordaland County, Norway between 1988 and 1997. Results The following variables were more frequent among patients with occipital lobe infarction compared with patients with infarcti...

  8. Identification of febrile seizure susceptibility genes : studies in mouse chromosome substitution strains and temporal lobe epilepsy patients

    NARCIS (Netherlands)

    Hessel, E.V.S.

    2010-01-01

    Febrile Seizures (FS) are the most common seizure type in children and recurrent FS are a risk factor for developing temporal lobe epilepsy (TLE). Although the mechanisms underlying FS are largely unknown, recent family, twin and animal studies indicate that genetics are important in FS

  9. Identification of febrile seizure susceptibility genes : studies in mouse chromosome substitution strains and temporal lobe epilepsy patients

    NARCIS (Netherlands)

    Hessel, E.V.S.

    2010-01-01

    Febrile Seizures (FS) are the most common seizure type in children and recurrent FS are a risk factor for developing temporal lobe epilepsy (TLE). Although the mechanisms underlying FS are largely unknown, recent family, twin and animal studies indicate that genetics are important in FS susceptibili

  10. Neonatal status of twins

    Directory of Open Access Journals (Sweden)

    Božinović Dragica

    2012-01-01

    Full Text Available Multiple pregnancy is a pregnancy where more than one fetus develops simultaneously in the womb, as a result of the ovulation and fertilization of more than one egg. It is relatively rare in humans and represents the rest of the phylogenetic stages. The most common are twins and they indicate the development of two fetuses in the womb. The frequency of twin pregnancies is about 1%. Multiple pregnancies belong to a group of high-risk pregnancies because of the many complications that occur during the pregnancy: higher number of premature deliveries, bleeding, early neonatal complications and higher perinatal morbidity and mortality. Such pregnancies and infants require greater supervision and monitoring. The aim of this study was to determine the percentage of baby twins born at the maternity ward of the General Hospital in Prokuplje and their morbidity and mortality. Data on the total number of deliveries, number of twins, parity and maternal age, gestational age, body weight of twins, method of delivery, Apgar score and perinatal mortality were collected and statistically analyzed by means of retrospective analysis of operative birth and neonatal protocol for 6 years (2005 of 2010. Out of 4527 mothers who gave birth 43 were pairs of twins, or 0.95% of women gave birth to twins. These babies are more likely born by Caesarean section, but delivered with slightly lower birth weight.

  11. The Improved Power of the Central Lobe in the Beam Combination and High Power Output

    Institute of Scientific and Technical Information of China (English)

    LIU Hou-Kang; WEI Yun-Rong; DONG Jing-Xing; LOU Qi-Hong; XUE Yu-Hao; LI Zhen; HE Bing; ZHOU Jun; DING Ya-Qian; JIAO Meng-Li; LIU Chi; QI Yun-Feng

    2012-01-01

    In order to increase the power fraction of the central lobe in the coherent beam combination of lasers in an array,the effects of the distance factor of near-field distribution on far-field interference patterns are calculated and demonstrated experimentally.An improved beam array of interwoven distribution is demonstrated to enable the power in the central lobe to reach 41%.An optimized mirror array is carefully designed to obtain a high duty ratio,which is up to 53.3% at a high power level.By using these optimized methods and designs,the passive phase locking of eight Yb-doped fiber amplifiers with ring cavities are obtained,and a pleasing interference pattern with 87% visibility is observed.The maximum coherent output power of the system is up to 1066 W.%In order to increase the power fraction of the central lobe in the coherent beam combination of lasers in an array, the effects of the distance factor of near-field distribution on far-field interference patterns are calculated and demonstrated experimentally. An improved beam array of interwoven distribution is demonstrated to enable the power in the central lobe to reach 41%. An optimized mirror array is carefully designed to obtain a high duty ratio, which is up to 53.3% at a high power level. By using these optimized methods and designs, the passive phase locking of eight Yb-doped fiber amplifiers with ring cavities are obtained, and a pleasing interference pattern with 87% visibility is observed. The maximum coherent output power of the system is up to 1066 W.

  12. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2016-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  13. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  14. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-31

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  15. Near- and Far-Field Optical Response of Eccentric Nanoshells.

    Science.gov (United States)

    Peña-Rodríguez, Ovidio; Díaz-Núñez, Pablo; Rodríguez-Iglesias, Vladimir; Montaño-Priede, Luis; Rivera, Antonio; Pal, Umapada

    2017-12-01

    We study the optical response of eccentric nanoshells (i.e., spherical nanoparticles with an eccentric spherical inclusion) in the near and the far field through finite-difference time-domain simulations. Plasmon hybridization theory is used to explain the obtained results. The eccentricity generates a far-field optical spectrum with various plasmon peaks. The number, position, and width of the peaks depend on the core offset. Near-field enhancements in the surroundings of these structures are significantly larger than those obtained for equivalent concentric nanoshells and, more importantly, they are almost independent of the illumination conditions. This opens up the door for using eccentric nanoshells in applications requiring intense near-field enhancements.

  16. Far-field superresolution by imaging of resonance scattering

    KAUST Repository

    Schuster, Gerard T.

    2014-10-31

    We show that superresolution imaging in the far-field region of the sources and receivers is theoretically and practically possible if migration of resonant multiples is employed. A resonant multiple is one that bounces back and forth between two scattering points; it can also be the multiple between two smoothly varying interfaces as long as the reflection wave paths partially overlap and reflect from the same Fresnel zone. For a source with frequency f, compared to a one-way trip, N round trips in propagating between two scatterers increase the effective frequency by 2N × f and decrease the effective wavelength by λ/(2N). Thus, multiples can, in principle, be used as high-frequency probes to estimate detailed properties of layers. Tests with both synthetic and field data validate this claim. Improved resolution by multiple imaging is not only feasible for crustal reflections, but might be applicable to mantle and core reverberations recorded by earthquake seismologists.

  17. A Java Interface for Roche Lobe Calculations

    Science.gov (United States)

    Leahy, D. A.; Leahy, J. C.

    2015-09-01

    A JAVA interface for calculating various properties of the Roche lobe has been created. The geometry of the Roche lobe is important for studying interacting binary stars, particularly those with compact objects which have a companion which fills the Roche lobe. There is no known analytic solution to the Roche lobe problem. Here the geometry of the Roche lobe is calculated numerically to high accuracy and made available to the user for arbitrary input mass ratio, q.

  18. Far-Field Tsunami Hazard in New Zealand Ports

    Science.gov (United States)

    Borrero, Jose C.; Goring, Derek G.; Greer, S. Dougal; Power, William L.

    2015-03-01

    We present the results of a numerical modeling study investigating the effects of far-field tsunamis in New Zealand ports. Four sites (Marsden Point, Tauranga, Harbor, Port Taranaki and Lyttelton Harbor) were selected based on a combination of factors such as economic importance and the availability of historical and/or instrumental data. Numerical models were created using the ComMIT tsunami modeling tool and the Method Of Splitting Tsunami (MOST) hydrodynamic model. Comparison of model results to measured data from recent historical events showed that, for particular sites and events, the model correlated well with the timing and amplitude of the observed tsunami, and, in most cases, there was generally good agreement between the and modeled tsunami heights and current speeds. A sensitivity analysis for tsunami heights and current speeds was conducted using a suite of large ( M W 9) tsunamigenic earthquake sources situated at regular 15° intervals in azimuth along the Pacific Rim while another set of scenarios focused on regional tsunami sources in the Southwest Pacific. Model results were analyzed for tsunami heights and current speeds as a function of the source region. In terms of currents, the analysis identified where speeds were greatest and which source was responsible. Results suggested that tsunamis originating from Central America produced the strongest response in New Zealand. The modeling was also used to determine the timing and duration of potentially dangerous current speeds as well as minimum `safe depths' for vessel evacuation offshore. This study was motivated by the desire to reduce damage and operational losses via improved forecasting of far-field tsunamis at New Zealand ports. It is important that forecasts are accurate since tsunami damage to ships and facilities is expensive and can be mitigated given timely warnings and because preventable false alarms are also costly in terms of lost productivity. The modeling presented here will

  19. Twin-twin Transfusion Syndrome with a Single Ectopic Kidney in a Twin Donor. Case Presentation

    Directory of Open Access Journals (Sweden)

    Gerardo Rogelio Robaina Castellanos

    2016-10-01

    Full Text Available Twin-twin Transfusion Syndrome presents more frequently in diamniotic monochromic twins. In advanced stages and without prenatal intervention, is associated to high rates of peri natal mortality and neurological sequel in the survivors. It is presented a case of a pair of twins with severe depression at birth in which it was diagnosed a Twin-twin Transfusion Syndrome, later confirmed with the presence of anemia in the donor twin and polycythemia in the receptor twin. Both twins had an unfavourable evolution with an early neonatal death. Necropsy findings were comparable with secondary damage to the syndrome, with the particularity that both had evidences of pulmonary infection and a renal malformation in the donor twin which is not included in the proper malformations of this syndrome. The objective of this work is to point out the essential elements for the diagnosis and antenatal treatment for this disease through the peculiarities of the presented case.

  20. Fullerton Virtual Twin Study.

    Science.gov (United States)

    Segal, Nancy L

    2006-12-01

    Virtual twins (VTs; same-age unrelated siblings reared together from early infancy) have been studied at California State University (CSU), Fullerton since 1991. The current sample includes over 130 pairs. Past and current research have research have focused on siblings' similarities and differences in general intelligence and body size. Future research in these areas will continue as new pairs continue to be identified. These studies will be supplemented by analyses of personality, social relations and adjustment using monozygotic (MZ) twins, dizygotic (DZ) twins, full siblings and friends, as well as new VTs, who have participated in Twins, Adoptees, Peers and Siblings (TAPS), a collaborative project conducted between CSU Fullerton and the University of San Francisco, from 2002 to 2006.

  1. Craniofacial anomalies in twins.

    Science.gov (United States)

    Keusch, C F; Mulliken, J B; Kaplan, L C

    1991-01-01

    Studies of twins provide insight into the relative contribution of genetic and environmental factors in the causality of structural anomalies. Thirty-five affected twin pairs were identified from a group of 1114 patients with congenital craniofacial deformities evaluated from 1972 to 1989. Forty-three of these 70 twins exhibited one or more craniofacial anomalies; these were analyzed for dysmorphic characteristics, zygosity, concordance, and family history. The anomalies were categorized into two groups: malformations and deformations. The malformations (n = 36) included hemifacial microsomia (n = 10), cleft lip and palate (n = 8), cleft palate (n = 4), rare facial cleft (n = 2), craniosynostosis (n = 2), Binder syndrome (n = 2), Treacher Collins syndrome (n = 2), craniopagus (n = 2), CHARGE association (n = 1), frontonasal dysplasia (n = 2), and constricted ears (n = 1). The deformations (n = 7) included plagiocephaly (n = 5), hemifacial hypoplasia (n = 1), and micrognathia (n = 1). Twenty-one monozygotic and 14 dizygotic twin pairs were identified. The concordance rate was 33 percent for monozygotic twins and 7 percent for dizygotic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Twin delivery: how should the second twin be delivered?

    Science.gov (United States)

    Olofsson, P; Rydhström, H

    1985-11-01

    In a series of 803 pairs of twins born between 1973 and 1982, 0.33% of second twins were delivered by cesarean section after vaginal delivery of the first twin. During the last year the frequency has increased to 7%, calling attention to the problem of declining obstetric skills and experience. This has caused us to update the routines of intrapartum management of twin gestations. In the present program only commonly available obstetric techniques are used. The potentially hazardous twin delivery is excluded from a trial of vaginal delivery. Hopefully, the program will help other obstetricians to decide in favor of vaginal delivery in selected twin gestations.

  3. Occipital lobe infarctions are different

    Directory of Open Access Journals (Sweden)

    Halvor Naess

    2007-09-01

    Full Text Available Halvor Naess, Ulrikke Waje-Andreassen, Lars ThomassenDepartment of Neurology, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayObjectives: We hypothesized that occipital lobe infarctions differ from infarctions in other locations as to etiology, risk factors and prognosis among young adults.Methods: Location, etiology, risk factors and long-term outcome were evaluated among all young adults 15–49 years suffering from cerebral infarction in Hordaland County, Norway between 1988 and 1997.Results: The following variables were more frequent among patients with occipital lobe infarction compared with patients with infarctions located elsewhere: younger age (P < 0.001, female sex (P = 0.016, prothrombotic state (P = 0.005 and lack of hypertension (P = 0.001. There was no difference as to long-term mortality or recurrence of cerebral infarction. Conclusion: Occipital lobe infarctions differ from infarctions in other locations among young adults. This may have important etiologic and therapeutical implications that need further studies.Keywords: cerebral infarction, occipital lobe, young adults

  4. Simultaneous drift, microsaccades, and ocular microtremor measurement from a single noncontact far-field optical sensor

    Science.gov (United States)

    Ryle, James P.; Vohnsen, Brian; Sheridan, John T.

    2015-02-01

    We report on the combined far-field measurement of the three involuntary eye movements, drift, microsaccades, and ocular microtremor (OMT), using a noncontact far-field optical method. We review the significance of the smallest and least measured, and thus least understood, of the three, OMT. Using modern digital imaging techniques, we perform detailed analysis, present experimental results, and examine the extracted parameters using a noncontact far-field sensor. For the first time, in vivo noncontact measurements of all three fixational in-plane movements of the human eye are reported, which simultaneously provide both the horizontal (left-right) and vertical (up-down) displacement results.

  5. Fractal characteristics of far-field diffraction patterns for two-dimensional Thue-Morse quasicrystals

    Institute of Scientific and Technical Information of China (English)

    YANG Ming-yang; ZHOU Jun; L Petti; S De Nicola; P Mormile

    2011-01-01

    We report a numerical method to analyze the fractal characteristics of far-field diffraction patterns for two-dimensional Thue-Morse(2-D TM) structures.The far-field diffraction patterns of the 2-D TM structures can be obtained by the numerical method,and they have a good agreement with the experimental ones.The analysis shows that the fractal characteristics of far-field diffraction patterns for the 2-D TM structures are determined by the inflation rule,which have potential applications in the design of optical diffraction devices.

  6. The Texas Twin Project.

    Science.gov (United States)

    Harden, K Paige; Tucker-Drob, Elliot M; Tackett, Jennifer L

    2013-02-01

    Socioeconomic position, racial/ethnic minority status, and other characteristics of the macro-environment may be important moderators of genetic influence on a wide array of psychosocial outcomes. Designed to maximize representation of low socioeconomic status families and racial/ethnic minorities, the Texas Twin Project is an ongoing study of school-age twins (preschool through 12th grade) enrolled in public schools in the Austin, Texas and Houston, Texas metropolitan areas. School rosters are used to identify twin families from a target population with sizable populations of African American (18%), Hispanic/Latino (48%), and non-Hispanic White (27%) children and adolescents, over half of whom meet US guidelines for classification as economically disadvantaged. Initial efforts have focused on a large-scale, family-based survey study involving both parent and child reports of personality, psychopathology, physical health, academic interests, parent-child relationships, and aspects of the home environment. In addition, the Texas Twin Project is the basis for an in-laboratory study of adolescent decision-making, delinquency, and substance use. Future directions include geographic expansion of the sample to the entire state of Texas (with a population of over 25 million) and genotyping of participating twins.

  7. Hypoalbuminemia in Donors with Twin-Twin Transfusion Syndrome

    NARCIS (Netherlands)

    Verbeek, L.; Middeldorp, J. M.; Hulzebos, C. V.; Oepkes, D.; Walther, F. J.; Lopriore, E.

    2013-01-01

    Objective: To estimate the differences in albumin levels between donors and recipients with twin-twin transfusion syndrome (TTTS). Methods: We performed a matched case-control study including twin pairs with TTTS treated conservatively (conservative group) or with fetoscopic laser surgery (laser gro

  8. Far-field Diffraction Properties of Annular Walsh Filters

    Directory of Open Access Journals (Sweden)

    Pubali Mukherjee

    2013-01-01

    Full Text Available Annular Walsh filters are derived from the rotationally symmetric annular Walsh functions which form a complete set of orthogonal functions that take on values either +1 or −1 over the domain specified by the inner and outer radii of the annulus. The value of any annular Walsh function is taken as zero from the centre of the circular aperture to the inner radius of the annulus. The three values 0, +1, and −1 in an annular Walsh function can be realized in a corresponding annular Walsh filter by using transmission values of zero amplitude (i.e., an obscuration, unity amplitude and zero phase, and unity amplitude and phase, respectively. Not only the order of the Walsh filter but also the size of the inner radius of the annulus provides an additional degree of freedom in tailoring of point spread function by using these filters for pupil plane filtering in imaging systems. In this report, we present the far-field amplitude characteristics of some of these filters to underscore their potential for effective use in several demanding applications like high-resolution microscopy, optical data storage, microlithography, optical encryption, and optical micromanipulation.

  9. Dialysis for twins

    DEFF Research Database (Denmark)

    Gramkow, Ann-Maria; Aarup, Michael; Andersen, L. L. T.

    2014-01-01

    A 32-year-old woman with known stage-4 chronic kidney disease due to lupus nephritis presented with twin pregnancy after in vitro fertilization at a gestational age of 24 weeks + 3 days because of imminent preterm labour. Repeated ultrasound evaluations confirmed intrauterine growth restriction...... in both twins and polyhydramnios as the cause of imminent preterm labour. After initiation of haemodialysis treatment, ultrasound evaluation showed a significant decrease in amniotic fluids, and also reduction in blood urea nitrogen and in clinical complaints could be observed. At a gestational age of 28...... weeks + 4 days, delivery was performed by Caesarean section. This case study shows that effective treatment of elevated uraemic toxins significantly reduced the morbidity risks of the twins....

  10. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Christiansen, Lene; Kyvik, Kirsten Ohm;

    2013-01-01

    decade of combining questionnaire and survey data with national demographic, social, and health registers in Statistics Denmark. Second, we describe our most recent data collection effort, which was conducted during the period 2008-2011 and included both in-person assessments of 14,000+ twins born 1931......Over the last 60 years, the resources and the research in the Danish Twin Registry (DTR) have periodically been summarized. Here, we give a short overview of the DTR and a more comprehensive description of new developments in the twenty-first century. First, we outline our experience over the last......-1969 and sampling of biological material, hereby expanding and consolidating the DTR biobank. Third, two examples of intensively studied twin cohorts are given. The new developments in the DTR in the last decade have facilitated the ongoing research and laid the groundwork for new research directions....

  11. Maternal nutrition in twin pregnancy.

    Science.gov (United States)

    Campbell, D M; MacGillivray, I; Tuttle, S

    1982-01-01

    Energy and protein intake as measured by 24-hour urinary nitrogen values are similar in twin and singleton pregnancies. The relationship between urinary nitrogen and nitrogen intake is equally significant in twin and singleton pregnancies. Dietary zinc, copper, and iron are not different in women with twins, nor are the levels of these elements in plasma. These observations are surprising in view of the extra fetal demands on the mother and the different adaptation of twin pregnancies.

  12. Relativistic twins or sextuplets?

    CERN Document Server

    Sheldon, E S

    2003-01-01

    A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.

  13. Imaging of conjoined twins

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kieran [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Kiely, Edward M.; Spitz, Lewis [Great Ormond Street Hospital for Children, Department of Surgery, London (United Kingdom)

    2006-09-15

    The incidence of conjoined twins is estimated to be around 1 in 250,000 live births. There is a distinct female predominance. In this paper the imaging of conjoined twins both antenatally and postnatally is reviewed, in particular taking into consideration recent advances with multidetector CT. Accurate counselling of parents regarding the likely outcome of the pregnancy and the likelihood of successful separation is dependent on good prenatal imaging with ultrasound and MRI. Planning of postnatal surgical separation is aided by accurate preoperative imaging which, depending on the conjoined area, will encompass many imaging modalities, but often relies heavily on CT scanning. (orig.)

  14. The Twin Interdisciplinary Neuroticism Study

    NARCIS (Netherlands)

    Riese, Harriette; Rijsdijk, Fruehling V.; Snieder, Harold; Ormel, Johan

    The Twin Interdisciplinary Neuroticism Study (TWINS) is a three-wave study including >800 twin pairs from the northern part of the Netherlands. The aim of the study is to unravel why neuroticism reflects vulnerability to mental disorders. In this study, we focus on possible mechanisms underlying

  15. Distally lobed integuments in some Angiosperm ovules

    NARCIS (Netherlands)

    Heel, van W.A.

    1970-01-01

    In this treatise ‘De l’Ovule’ Warming (1878) remarked that although the borders of the integuments grow uniformly, very rarely a division into lobes can be observed. He mentioned Symplocarpus foetida (inner integument four-lobed), Lagarosiphon schweinfurthii (outer integument four- or five-lobed)

  16. Distally lobed integuments in some Angiosperm ovules

    NARCIS (Netherlands)

    Heel, van W.A.

    1970-01-01

    In this treatise ‘De l’Ovule’ Warming (1878) remarked that although the borders of the integuments grow uniformly, very rarely a division into lobes can be observed. He mentioned Symplocarpus foetida (inner integument four-lobed), Lagarosiphon schweinfurthii (outer integument four- or five-lobed) an

  17. One-dimensional Fibonacci grating for far-field super-resolution imaging.

    Science.gov (United States)

    Wu, Kedi; Wang, Guo Ping

    2013-06-15

    One-dimensional Fibonacci gratings are used to transform evanescent waves into propagating waves for far-field super-resolution imaging. By detecting far-field intensity distributions of light through objects in front of the Fibonacci grating in free space, we can observe the objects with nearly λ/9 spatial resolution. Analytical results are verified by numerical simulations. We also discuss the effect of sampling error on imaging resolution of the system.

  18. Temporal Lobe Epilepsy in Children

    Science.gov (United States)

    Nickels, Katherine C.; Wong-Kisiel, Lily C.; Moseley, Brian D.; Wirrell, Elaine C.

    2012-01-01

    The temporal lobe is a common focus for epilepsy. Temporal lobe epilepsy in infants and children differs from the relatively homogeneous syndrome seen in adults in several important clinical and pathological ways. Seizure semiology varies by age, and the ictal EEG pattern may be less clear cut than what is seen in adults. Additionally, the occurrence of intractable seizures in the developing brain may impact neurocognitive function remote from the temporal area. While many children will respond favorably to medical therapy, those with focal imaging abnormalities including cortical dysplasia, hippocampal sclerosis, or low-grade tumors are likely to be intractable. Expedient workup and surgical intervention in these medically intractable cases are needed to maximize long-term developmental outcome. PMID:22957247

  19. Temporal Lobe Epilepsy in Children

    Directory of Open Access Journals (Sweden)

    Katherine C. Nickels

    2012-01-01

    Full Text Available The temporal lobe is a common focus for epilepsy. Temporal lobe epilepsy in infants and children differs from the relatively homogeneous syndrome seen in adults in several important clinical and pathological ways. Seizure semiology varies by age, and the ictal EEG pattern may be less clear cut than what is seen in adults. Additionally, the occurrence of intractable seizures in the developing brain may impact neurocognitive function remote from the temporal area. While many children will respond favorably to medical therapy, those with focal imaging abnormalities including cortical dysplasia, hippocampal sclerosis, or low-grade tumors are likely to be intractable. Expedient workup and surgical intervention in these medically intractable cases are needed to maximize long-term developmental outcome.

  20. Recovering scattering obstacles by multi-frequency phaseless far-field data

    Science.gov (United States)

    Zhang, Bo; Zhang, Haiwen

    2017-09-01

    It is well known that the modulus of the far-field pattern (or phaseless far-field pattern) is invariant under translations of the scattering obstacle if only one plane wave is used as the incident field, so the shape but not the location of the obstacle can be recovered from the phaseless far-field data. This paper aims to devise an approach to break the translation invariance property of the phaseless far-field pattern. To this end, we make use of the superposition of two plane waves rather than one plane wave as the incident field. In this paper, it is mathematically proved that the translation invariance property of the phaseless far-field pattern can indeed be broken if superpositions of two plane waves are used as the incident fields for all wave numbers in a finite interval. Furthermore, a recursive Newton-type iteration algorithm in frequencies is also developed to numerically recover both the location and the shape of the obstacle simultaneously from multi-frequency phaseless far-field data. Numerical examples are also carried out to illustrate the validity of the approach and the effectiveness of the inversion algorithm.

  1. Occipital lobe infarctions are different

    OpenAIRE

    Halvor Naess; Ulrikke Waje-Andreassen; Lars Thomassen

    2007-01-01

    Halvor Naess, Ulrikke Waje-Andreassen, Lars ThomassenDepartment of Neurology, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayObjectives: We hypothesized that occipital lobe infarctions differ from infarctions in other locations as to etiology, risk factors and prognosis among young adults.Methods: Location, etiology, risk factors and long-term outcome were evaluated among all young adults 15–49 years suffering from cerebral infarction in Hordaland County, Norw...

  2. Identical Twins Raised Apart

    Science.gov (United States)

    Farnsworth, David L.

    2015-01-01

    This article describes a bivariate data set that is interesting to students. Indeed, this particular data set, which involves twins and IQ, has sparked more student interest than any other set that I have presented. Specific uses of the data set are presented.

  3. Sleep Terrors in Twins

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-12-01

    Full Text Available In an attempt to clarify the genetic and environmental causes of sleep terrors in childhood, reasearchers in Canada followed 390 pairs of monozygotic and dizygotic twins by assessing the frequency of sleep terrors at 18 and 30 months of age using a questionnaire administered to the biological mothers.

  4. Twin Hub Network (poster)

    NARCIS (Netherlands)

    Kreutzberger, E.D.; Konings, J.W.

    2014-01-01

    Twin hub network, a European Interreg IVB project, aims at making intermodal rail transport within, to and from North West Europe more competitive, in particular between seaports and inland terminals. Improving rail competitiveness enables to shift freight flows from road to rail, providing a more s

  5. Amelia in Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Davari Tanha Fatemeh

    2009-04-01

    Full Text Available Limb bud first appears during the third week of gestation with the upper limb buds appearing a few days before the lower limb buds. Complete absence of one or more limbs, called Amelia, occurs prior to the eighth week of gestation. We report a case of Amelia in a twin gestation.

  6. TWIN BLOCK (Studi Pustaka

    Directory of Open Access Journals (Sweden)

    Evie Lamtiur

    2015-08-01

    Full Text Available Young patients with class II skeletal malocclusion are often found. To avoid further discrepancy of this case, myofunctional therapy is one of the options. Functional appliance often used for such treatment. Functional appliance has been modified since activator was introduced by Andresen. With its bulky shape, activator makes difficulty for patient to speak and eat. Patient unable to wear it full time due to uncomfortness and negative facial appearance. In 1977, Clark developed twin block to overcome the weakness of previous appliances. A more simple design allows patient to be more comfortable and willing to wear it longer. Twin block is myofunctional appliance to reposition the mandible forward for skeletal class II correction with retruded mandible. This paper describes the design, clinical management effects of twin block treatment and brief case presentation using twin block appliance. Similar to the study reports found, this case revealed improvement of facial appearance, decrease overjet and overbite, improvement of molar relationship and good compliance of patient.

  7. Twin-twin transfusion syndrome - diagnosis and prognosis

    Directory of Open Access Journals (Sweden)

    Hajrić-Egić Amira

    2003-01-01

    Full Text Available Twin-twin transfusion syndrome is a serious complication of monozygotic, monochorionic, diamniotic twins resulting from transplacental vascular communications. In this syndrome blood is thought to be shunted from one twin - donor,who develops anaemia,growth retardation and oligoamnios, to the other twin - recipient,who becomes plethoric,macrosomic and develops polyhydroamnios. The incidence of twin-twin transfusion syndrome ranges from 5-15% of all twin pregnancies. If this condition develops in the second trimester, it is usually associated with spontaneous abortion and death of one or both fetuses before viability. Developing the syndrome in the third trimester has better perinatal outcome. Mortality rates ranging from 56%-100%, depending on gestational age and severity of the syndrome. The ultrasound criterias for diagnosis, in this study,were the presence of twins of the same sex with discordant growth, with oligohydroamnios in one twin sac and polyhydroamnios in the other one, one placenta and thin membrane between twins. The present study shows clinical course of 14 cases and value of Doppler ultrasound to analyze the usefulness of umbilical artery blood flow velocimetry for predicting the risk of twin-twin transfusion syndrome. 14 twin pregnancies with twin-twin transfusion syndrome were diagnosed during the last four years period and prospectivelly followed. 9 cases were diagnosed before the completion od 28 weeks of gestation.The mean gestational age was 21,6_+4,2 weeks at diagnosis and 23,2+_3,6 weeks at delivery. 5 cases were diagnosed after 28 weeks of gestation. The mean gestational age in this group was 29,6+_2,1 weeks at diagnosis and 33+_3,3 weeks at delivery. The survival rate in this study was 29%(8/28.9 cases ended in spontaneous abortion between 18th and 27th weeks of pregnancy (table 1 and 5 in premature labor (table 2.There were 7 intrauterine death (5 at admission and 2 few days after admission and 13 neonatal deaths

  8. Mitral valve regurgitation in twins

    DEFF Research Database (Denmark)

    Bakkestrøm, Rine; Larsen, Lisbeth Aagaard; Møller, Jacob Eifer

    2016-01-01

    BACKGROUND: Smaller observational studies have suggested familial clustering of mitral regurgitation (MR). Using a large twin cohort, the aims were to assess MR concordance rates and assess mortality in MR twins and unaffected cotwins. METHODS: Through the Danish Twin Registry, twins...... with an International Classification of Diseases, Eighth Revision and Tenth Revision diagnosis code of MR born 1880-1989 were identified and proband-wise concordance rates were calculated. To assess whether having a cotwin with MR affected survival, 10 matched twins without MR (n = 5,575) were selected for each MR twin...... (n = 562), and all-cause mortality rates were assessed. RESULTS: Among the 87,432 twins alive January 1, 1977, or later, 494 (0.57%) MR individuals were identified. Six MR concordant pairs were found, of which 3 were monozygotic. Proband-wise concordance rate when accounting for right censoring...

  9. Brazilian Twin Registry: A Bright Future for Twin Studies/Twin Research: Twin Study of Alcohol Consumption and Mortality; Oxygen Uptake in Adolescent Twins/In the News: Superfecundated Twins In Vietnam; Adolescent Twin Relations; Twin and Triplet Co-Workers; A Special Twin Ultrasound; Monozygotic Twins With Different Skin Color; Identical Twin Returns from Space.

    Science.gov (United States)

    Segal, Nancy L

    2016-06-01

    The establishment of the Brazilian Twin Registry for the study of genetic, social, and cultural influences on behavior is one of eleven newly funded projects in the Department of Psychology at the University of São Paulo. These 11 interrelated projects form the core of the university's Center for Applied Research on Well-Being and Human Behavior. An overview of the planned twin research and activities to date is presented. Next, two recent twin studies are reviewed, one on the relationship between alcohol consumption and mortality, and the other on factors affecting maximal oxygen uptake. Twins cited in the media include the first identified superfecundated twins in Vietnam, adolescent twin relations, twins and triplets who work together, monozygotic twins with different skin tones and a co-twin control study that addresses the effects of space travel.

  10. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    2009-01-01

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  11. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  12. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    2009-01-01

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  13. Reared-Apart Chinese Twins: Chance Discovery/Twin-Based Research: Twin Study of Media Use; Twin Relations Over the Life Span; Breast-Feeding Opposite-Sex Twins/Print and Online Media: Twins in Fashion; Second Twin Pair Born to Tennis Star; Twin Primes; Twin Pandas.

    Science.gov (United States)

    Segal, Nancy L

    2017-04-01

    A January 2017 reunion of 10-year-old reared-apart Chinese twin girls was captured live on ABC's morning talk show Good Morning America, and rebroadcast on their evening news program Nightline. The twins' similarities and differences, and their participation in ongoing research will be described. This story is followed by reviews of twin research concerning genetic and environmental influences on media use, twin relations across the lifespan and the breast-feeding of opposite-sex twins. Popular interest items include twins in fashion, the second twin pair born to an internationally renowned tennis star, twin primes and twin pandas.

  14. Minimal Mirror Twin Higgs

    CERN Document Server

    Barbieri, Riccardo; Harigaya, Keisuke

    2016-01-01

    In a Mirror Twin World with a maximally symmetric Higgs sector the little hierarchy of the Standard Model can be significantly mitigated, perhaps displacing the cutoff scale above the LHC reach. We show that consistency with observations requires that the Z2 parity exchanging the Standard Model with its mirror be broken in the Yukawa couplings. A minimal such effective field theory, with this sole Z2 breaking, can generate the Z2 breaking in the Higgs sector necessary for the Twin Higgs mechanism, and has constrained and correlated signals in invisible Higgs decays, direct Dark Matter Detection and Dark Radiation, all within reach of foreseen experiments. For dark matter, both mirror neutrons and a variety of self-interacting mirror atoms are considered. Neutrino mass signals and the effects of a possible additional Z2 breaking from the vacuum expectation values of B-L breaking fields are also discussed.

  15. Emergence of Digital Twins

    OpenAIRE

    Datta, Shoumen Palit Austin

    2016-01-01

    Multiple forms of digital transformation are imminent. Digital Twins represent one concept. It is gaining momentum because it may offer real-time transparency. Rapid diffusion of digital duplicates faces hurdles due to lack of semantic interoperability between architectures, standards and ontologies. The technologies necessary for automated discovery are in short supply. Progression of the field depends on convergence of information technology, operational technology and protocol-agnostic tel...

  16. Nutrition in twin pregnancy.

    Science.gov (United States)

    MacGillivray, I

    1979-01-01

    The urinary nitrogen output appears to be related to both protein and energy intake, so that women having heavier babies probably eat more, although this may simply mean that they are larger women. Women with twin pregnancies have been found to have a lesser urinary nitrogen output, but it seems unlikely that this be due to lower intakes. They might simply utilize their diet more efficiently--a hypothesis that is now being tested.

  17. Tribute to dr louis keith: twin and physician extraordinaire/twin research reports: influences on asthma severity; chimerism revisited; DNA strand break repair/media reports: twins born apart; elevated twin frequencies; celebrity father of twins; conjoined twinning.

    Science.gov (United States)

    Segal, Nancy L

    2014-10-01

    The International Society for Twin Studies has lost a valued friend and colleague. Dr Louis Keith, Emeritus Professor of Obstetrics and Gynecology at Northwestern University, in Chicago, passed away on Sunday, July 6, 2014. His life and work with twins will be acknowledged at the November 2014 International Twin Congress in Budapest, Hungary. Next, twin research reports on the severity of asthma symptoms, a case of chimerism, and factors affecting DNA breakage and repair mechanisms are reviewed. Media reports cover twins born apart, elevated twin frequencies, a celebrity father of twins, and a family's decision to keep conjoined twins together.

  18. Socioeconomic position and twins' health

    DEFF Research Database (Denmark)

    Osler, Merete; McGue, Matt; Christensen, Kaare

    2007-01-01

    of middle-aged Danish twins was conducted in 1998-99. The study population included 1266 like-sex twin pairs [52.5% monozygotic (MZ) and 47.6% dizygotic (DZ)]. Data were obtained on childhood and adult social class and on height, BMI, grip strength, depression symptoms, self-rated health, cognitive function......, prenatal and rearing environmental factors from environmental factor later in life, we compared the health status among male and female twin pairs who lived together during childhood and were discordant or concordant on adult socioeconomic position. METHODS: A cross-sectional survey among a random sample......, physical activity, smoking, alcohol and food intake. RESULTS: The expected associations between the individual twins' adult social class and health measures were observed. Among DZ male twins discordant on adult social class, the higher social class twin was on average significantly taller and had higher...

  19. Twin-to-twin delivery time: neonatal outcome of the second twin.

    Science.gov (United States)

    Schneuber, Susanne; Magnet, Eva; Haas, Josef; Giuliani, Albrecht; Freidl, Thomas; Lang, Uwe; Bjelic-Radisic, Vesna

    2011-12-01

    To examine the effect of twin-to-twin delivery time (TTDT) on neonatal outcome. We evaluated twin deliveries >34 weeks of gestation. Twin pregnancies with both twins delivered by cesarean section and pregnancies with antenatal complications were excluded. We analyzed TTDT and neonatal outcomes of the second twin (umbilical arterial pH value (pH(art)), Apgar scores at 1, 5 and 10 minutes, need for intensive care). The study population was divided into two homogenous groups based on the mode of delivery: (A) vertex presentation and vaginal delivery of both twins, (B) vertex presentation and vaginal or vaginal operative delivery of twin I, breech or transverse presentation and vaginal breech delivery or cesarean section (CS) of twin II. A total of 207 twin pairs were included in our study. In Group A (n = 151) there were no significant correlations between TTDT and pH(art) or Apgar scores at 1,5 and 10 minutes of twin II (p = .156; 0.861; 0.151 and 0.384, respectively). In Group B (n = 56), the mean pH(art) of twin II was inversely correlated to TTDT, but not significantly (p = .417). TTDT was inversely related to 1-min and 5-min Apgar scores, but not significantly (p = .330; p = .138, respectively). The 10-min Apgar score showed no correlation with TTDT (p = .638). Increasing TTDT was not associated with adverse fetal outcome. Expectant management of the second twin appears possible and elapsed time alone does not appear to be an indication for intervention.

  20. Trojan twin planets

    Science.gov (United States)

    Dvorak, R.; Loibnegger, B.; Schwarz, R.

    2017-03-01

    The Trojan asteroids are moving in the vicinity of the stable Lagrange points L_4 and L_5 of the gas giants Jupiter, Uranus and Neptune. Their motion can be described and understood with the aid of the restricted three-body problem. As an extension of this problem we investigate how stable motion close to the Lagrange points of two massive bodies can exist. This configuration can be described as the Trojan Twin Problem when we regard the two additional bodies as having a mass significantly smaller than the the two primary bodies: a star in the center (m_1) and an additional Jupiter-like mass (m_2). Using this 4-body problem we have undertaken numerical investigations concerning possible stable "twin orbits". However, these two bodies (m_3 and m_4) in Trojan-like orbits may have quite different masses. We decided to choose 6 different scenaria for this problem: as primary body, m2, we have taken a Jupiter-like planet, a Saturn-like one, and a super-Earth with 10 Earthmasses (m_{Earth}) respectively. As quasi twin planets, we have used different mass ratios namely objects for m3 and m4 from 10m_{Earth} to Moon like ones. We found different stable configurations depending on the involved masses and the initial distances between the twins (always close to the Lagrange point). Although the formation of such a configuration seems to be not very probable we should not exclude that it exists regarding the huge number of planets even in our own galaxy. This model is of special interest when the most massive planet (m_2) is moving on an orbit in the habitable zone around a main sequence star. One can use our results of stable orbits of Trojan Twin Planets (or asteroids) for extrasolar systems having as second primary a Jupiter-like, a Saturn-like or a super-Earth like planet around a star similar to our Sun.

  1. Anomalous Feeding of the Left Upper Lobe.

    Science.gov (United States)

    Hazzard, Christopher; Itagaki, Shinobu; Lajam, Fouad; Flores, Raja M

    2016-09-01

    We report the case of a 53-year-old woman who presented with massive hemoptysis. Computed tomographic angiography revealed an anomalous vessel arising from the abdominal aorta, coursing anteriorly and through the diaphragm, and feeding the left upper lobe. At operation the vessel was found to anastomose to the left upper lobe lingula, which contained multiple vascular abnormalities and arteriovenous fistulas. The vessel was ligated, and the affected portion of the left upper lobe was resected. Anomalous systemic arterial supply of an upper lobe is an especially rare form of a Pryce type 1 abnormality. Recognition of these unusual anatomic variants is crucial to successful treatment and avoidance of adverse events.

  2. When You Are a Twin or Triplet

    Science.gov (United States)

    ... be a twin? Are you a twin and wonder why everyone thinks it's so special? It's fascinating ... the way the egg is fertilized when a woman becomes pregnant . In fraternal twins, two different eggs ...

  3. Near-field measurements of the even-order harmonics undetectable in far-field measurements

    Science.gov (United States)

    Moiseyev, Nimrod

    2016-12-01

    Even-order harmonics (EOHs) are generated for oriented molecules and for atoms under specific conditions. Here, we focus on the most common situations where EOHs are not observed in far-field measurements. We propose an experiment to show that the EOHs are produced close to the nucleus but are not detected in the far-field measurements due to destructive interferences of the propagated EOHs of the emitted radiation. However, Rydberg gas atoms (e.g., rubidium), which are out of the focus of the laser beam, are expected to be ionized due to their weak interaction with a specific EOH of helium, which is not observed by the far-field detector. The ionization energy of the Rydberg gas atoms should be in resonance with the single-photon energy of a specific EOH.

  4. Contemporary management of complicated monochorionic twins.

    Science.gov (United States)

    Moise, Karen Y; Kugler, Lisa; Jones, Tyra

    2012-01-01

    Monochorionic twins are at increased risk for unique complications including twin-twin transfusion syndrome (TTTS), selective intrauterine growth restriction (sIUGR), and twin-reversed arterial perfusion (TRAP) sequence. Twin-twin transfusion syndrome is treated with laser photocoagulation whereas selective reduction is an option in previable sIUGR or TRAP sequence. The nurse is integral in the management, education, care and support of women with complicated pregnancies. © 2012 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  5. Effects of asthma on stability of Wisconsin card sorting test measures A twin study

    Institute of Scientific and Technical Information of China (English)

    Yixiao Fu; Huaqing Meng; Hengshu Zhang; Lu Jia; Qinghua Luo

    2008-01-01

    BACKGROUND:The four measures used to assess the stability of the Wisconsin card sorting test (WEST),that is,the number of preservative errors,percentage of preservative errors,number of categories completed,and the number of trials to complete the first category,reflect the function of the frontal lobe.OBJECTIVE:This study was designed to investigate the effects of asthma on the stability of WCST measurements through the use of a twin study,and to analyze whether egg-type difference exists.DESIGN:A cohort study.SETTING:Mental Health Center,the First Affiliated Hospital of Chongqing Medical University.PARTICIPANTS:Fifty-nine pairs of twins,aged 6-16 years,were primarily selected from schools between August 2005 and February 2007 and the WeST and Zygosity identification test was applied.Twins with achromatopsia,severe upper limb diseases,somatic diseases,or mental disorders were excluded.According to disease history of asthmatic attack,children were assigned into asthma(n=16)and non-asthma(n=43)groups.METHODS:Four WCST measurements were determined in the 59 pairs of twins,and egg-type differences were identified in conjunction.RESULTS:All 59 pairs of twins were included in the final analysis.Among the pairs of twins,28 (48.5%)were monozygotic twins,and 31(52%)were dizygotic twins.Among the monozygotic and dizygotic twins,the number of preservative errors and percentage of preservative errors were significantly higher in the asthma group than in the non-asthma group(P0.05).CONCLUSION:Asthma may affect the stability of WCST measures,but egg-type differences do not exist.

  6. Twinning across the Developing World.

    Directory of Open Access Journals (Sweden)

    Jeroen Smits

    Full Text Available BACKGROUND: Until now, little was known about the variation in incidence of twin births across developing countries, because national representative data was lacking. This study provides the first comprehensive overview of national twinning rates across the developing world on the basis of reliable survey data. METHODS: Data on incidence of twinning was extracted from birth histories of women aged 15-49 interviewed in 150 Demographic and Health Surveys, held between 1987 and 2010 in 75 low and middle income countries. During the interview, information on all live births experienced by the women was recorded, including whether it was a singleton or multiple birth. Information was available for 2.47 million births experienced by 1.38 million women in a period of ten years before the interview. Twinning incidence was measured as the number of twin births per thousand births. Data for China were computed on the basis of published figures from the 1990 census. Both natural and age-standardized twinning rates are presented. RESULTS/CONCLUSIONS: The very low natural twinning rates of 6-9 per thousand births previously observed in some East Asian countries turn out to be the dominant pattern in the whole South and South-East Asian region. Very high twinning rates of above 18 per thousand are not restricted to Nigeria (until now seen as the world's twinning champion but found in most Central-African countries. Twinning rates in Latin America turn out to be as low as those in Asia. Changes over time are small and not in a specific direction. SIGNIFICANCE: We provide the most complete and comparable overview of twinning rates across the developing world currently possible.

  7. Twinning and heteropaternity in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Ely, John J; Frels, William I; Howell, Sue; Izard, M Kay; Keeling, Michale E; Lee, D Rick

    2006-05-01

    Unlike monozygotic (MZ) twins, dizygotic (DZ) twins develop from separate ova. The resulting twins can have different sires if the fertilizing sperm comes from different males. Routine paternity testing of a pair of same-sexed chimpanzee twins born to a female housed with two males indicated that the twins were sired by two different males. DNA typing of 22 short-tandem repeat (STR) loci demonstrated that these twins were not MZ twins but heteropaternal DZ twins. Reproductive data from 1926-2002 at five domestic chimpanzee colonies, including 52 twins and two triplets in 1,865 maternities, were used to estimate total twinning rates and the MZ and DZ components. The average chimpanzee MZ twinning rate (0.43%) equaled the average human MZ rate (0.48%). However, the chimpanzee DZ twinning rate (2.36%) was over twice the human average, and higher than all but the fertility-enhanced human populations of Nigeria. Similarly high twinning rates among African chimpanzees indicated that these estimates were not artifacts of captivity. Log-linear analyses of maternal and paternal effects on recurrent twinning indicated that females who twinned previously had recurrence risks five times greater than average, while evidence for a paternal twinning effect was weak. Chimpanzee twinning rates appear to be elevated relative to corresponding estimated human rates, making twinning and possibly heteropaternity more important features of chimpanzee reproductive biology than previously recognized.

  8. Twin Legacies: Victor and Vincent McKusick/Twin Studies: Twinning Rates I; Twinning Rates II; MZ Twin Discordance for Russell-Silver Syndrome; Twins' Language Skills/Headlines: Babies Born to Identical Twin Couples; Identity Exchange; Death of Princess Ashraf (Twin); Yahoo CEO Delivers Identical Twins.

    Science.gov (United States)

    Segal, Nancy L

    2016-04-01

    The lives of the illustrious monozygotic (MZ) twins, Victor A. and Vincent L. McKusick, are described. Victor earned the distinction as the 'Father of Medical Genetics', while Vincent was a legendary Chief Justice of the Maine Supreme Court. This dual biographical account is followed by two timely reports of twinning rates, a study of MZ twin discordance for Russell-Silver Syndrome (RSS) and a study of twins' language skills. Twin stories in the news include babies born to identical twin couples, a case of switched identity, the death of Princess Ashraf (Twin) and a new mother of twins who is also Yahoo's CEO.

  9. Estimating twin concordance for bivariate competing risks twin data

    DEFF Research Database (Denmark)

    Scheike, Thomas Harder; Holst, Klaus Kähler; von Bornemann Hjelmborg, Jacob

    2014-01-01

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experienced...... over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer...... the event of interest. Under the assumption that both twins are censored at the same time, we show how to estimate this probability in the presence of right censoring, and as a consequence, we can then estimate the casewise twin concordance. In addition, we can model the magnitude of within pair dependence...

  10. Two-dimensional Fibonacci grating for far-field super-resolution imaging

    Science.gov (United States)

    Wu, Kedi; Wang, Guo Ping

    2016-12-01

    A two-dimensional (2D) Fibonacci grating is used to transform evanescent waves into propagating waves for far-field super-resolution imaging. By detecting far-field intensity distributions of light field through objects in front of the 2D Fibonacci grating in free space at once, we can retrieve the image of objects with beyond λ/7 spatial resolution. We also find that the coherent illumination case can give a better resolution than incoherent illumination case by such 2D grating-assisted imaging system. The analytical results are verified by numerical simulation.

  11. Self-Similarity in Transverse Intensity Distributions in the Farfield Diffraction Pattern of Radial Walsh Filters

    Directory of Open Access Journals (Sweden)

    P. Mukherjee

    2014-01-01

    Full Text Available In a recent communication we reported the self-similarity in radial Walsh filters. The set of radial Walsh filters have been classified into distinct self-similar groups, where members of each group possess self-similar structures or phase sequences. It has been observed that, the axial intensity distributions in the farfield diffraction pattern of these self-similar radial Walsh filters are also self-similar. In this paper we report the self-similarity in the intensity distributions on a transverse plane in the farfield diffraction patterns of the self-similar radial Walsh filters.

  12. Analysis of ventilation systems subjected to explosive transients: far-field analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tang, P.K.; Andrae, R.W.; Bolstad, J.W.; Duerre, K.H.; Gregory, W.S.

    1981-11-01

    Progress in developing a far-field explosion simulation computer code is outlined. The term far-field implies that this computer code is suitable for modeling explosive transients in ventilation systems that are far removed from the explosive event and are rather insensitive to the particular characteristics of the explosive event. This type of analysis is useful when little detailed information is available and the explosive event is described parametrically. The code retains all the features of the TVENT code and allows completely compressible flow with inertia and choking effects. Problems that illustrate the capabilities and limitations of the code are described.

  13. Research on Far-Field Wavelet's Extraction and Application of Vertical Cable System

    Science.gov (United States)

    Wang, Xiangchun; Xiao, Qingsong; Xia, Changliang; Wu, Zhongliang; Xie, Chengliang

    2017-03-01

    In marine seismic exploration, ghost wave and bubble effect reduce the vertical resolution and interpretation accuracy seriously. Here firstly the far-field wavelet including source wavelet, ghost wave and bubble effect recorded by the vertical cable system (VCS) is extracted. Then, filters are designed using the extracted far-field wavelet to eliminate ghost wave, bubble effect and source wavelet. At last, the designed filters are applied to the seismic data of VCS. The results show that this method can eliminate ghost wave, bubble effect and source wavelet effectively and the vertical resolution of the seismic data is improved obviously.

  14. Numerical Methods for the Nonlinear Schrödinger Equation with Nonzero Far-field Conditions

    OpenAIRE

    2004-01-01

    In this paper we present numerical methods for the nonlinear Schrödinger equations (NLS) in the semiclassical regimes: \\[i \\vep\\; u_t^\\vep=-\\fl{\\vep^2}{2}\\;\\btu u^\\vep+V(\\bx)u^\\vep+ f(|u^\\vep|^2)u^\\vep, \\qquad \\bx\\in{\\Bbb R}^d,\\] with nonzero far-field conditions. A time-splitting cosine-spectral (TS-Cosine) method is presented when the nonzero far-field conditions are or can be reduced to homogeneous Neumann conditions, a time-splitting Chebyshev-spectral (TS-Chebyshe...

  15. Confronting Twin Paradox Acceleration

    Science.gov (United States)

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  16. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  17. Oliver Sacks: Our Correspondence About Twins/Twin Research: Vanishing Twins Syndrome; Discordant Sex in MZ Twins; Pregnancy Outcomes in IVF and ICSI Conceived Twins/Print and Media: Superfetated Twins; Twins Discordant for Smoking; Twins in Fashion; Yale University Twin Hockey Players; Conjoined Twin-Visiting Professor.

    Science.gov (United States)

    Segal, Nancy L

    2017-08-01

    The late neurologist and author, Oliver Sacks, published an insightful 1986 review of Marjorie Wallace's book, The Silent Twins, in the New York Times. Taking exception to his assertion about Sir Francis Galton, I wrote a letter to the Times' editor. The letter was unpublished, but it brought a wonderful response from Sacks himself that is reproduced and examined. Next, brief reviews of twin research concerning the vanishing twin syndrome (VTS), discordant sex in a monozygotic (MZ) twin pair, and multiple pregnancy outcomes from assisted reproductive technology (ART) are presented. This section is followed by popular coverage of superfetated twins, smoking-discordant co-twins, twins in fashion, Yale University twin hockey players, and a visiting professor who was a conjoined twin.

  18. Transformation: From Twin to Individual

    Science.gov (United States)

    Magagna, Jeanne

    2007-01-01

    This article explores some of the complexities of psychotherapy with an identical twin. The difficulty of developing in psychotherapy while so much of what is oneself is located in the other twin will also be explored. The use of the countertransference as a therapeutic method will be considered as the young person develops her unique, separate…

  19. Twin Studies of Atopic Dermatitis

    DEFF Research Database (Denmark)

    Elmose, Camilla; Thomsen, Simon Francis

    2015-01-01

    Aim. The aim of this study was to conduct a systematic review of population-based twin studies of (a) the concordance and heritability of AD and (b) the relationship between AD and asthma and, furthermore, to reinterpret findings from previous twin studies in the light of the emerging knowledge a...

  20. Twin methodology in epigenetic studies

    DEFF Research Database (Denmark)

    Tan, Qihua; Christiansen, Lene; von Bornemann Hjelmborg, Jacob

    2015-01-01

    Since the final decades of the last century, twin studies have made a remarkable contribution to the genetics of human complex traits and diseases. With the recent rapid development in modern biotechnology of high-throughput genetic and genomic analyses, twin modelling is expanding from analysis ...

  1. Twin Higgs WIMP Dark Matter

    CERN Document Server

    García, Isabel García; March-Russell, John

    2015-01-01

    Dark matter (DM) without a matter asymmetry is studied in the context of Twin Higgs (TH) theories in which the LHC naturalness problem is addressed. These possess a twin sector related to the Standard Model (SM) by a (broken) $\\mathbb{Z}_2$ symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realisation of the TH mechanism, the Fraternal Twin Higgs, with only a single generation of twin quarks and leptons, and $SU(3)'\\times SU(2)'$ gauge group. We show that a variety of natural twin-WIMP DM candidates are present (directly linked to the weak scale by naturalness), the simplest and most attractive being the $\\tau^\\prime$ lepton with a mass $m_{\\tau^\\prime} > m_{\\rm Higgs}/2$, although spin-1 $W^{\\prime\\pm}$ DM and multicomponent DM are also possible (twin baryons are strongly disfavoured by tuning). We consider in detail the dynamics of the possibly (meta)stable glueballs in the twin sector, the nature of the twin QCD phase transition, and possible new contributions to th...

  2. Hypertensive disorders in twin pregnancy

    NARCIS (Netherlands)

    J.G. Santema (Job); E. Koppelaar (Elin); H.C.S. Wallenburg (Henk)

    1995-01-01

    textabstractObjective: To compare the incidence and severity of pregnancy-induced hypertensive disorders in twin pregnancy and in singleton gestation. Study design: Case-control study in the setting of a University Hospital. Each pregnancy of a consecutive series of 187 twin pregnancies attending th

  3. A Computational Discriminability Analysis on Twin Fingerprints

    Science.gov (United States)

    Liu, Yu; Srihari, Sargur N.

    Sharing similar genetic traits makes the investigation of twins an important study in forensics and biometrics. Fingerprints are one of the most commonly found types of forensic evidence. The similarity between twins’ prints is critical establish to the reliability of fingerprint identification. We present a quantitative analysis of the discriminability of twin fingerprints on a new data set (227 pairs of identical twins and fraternal twins) recently collected from a twin population using both level 1 and level 2 features. Although the patterns of minutiae among twins are more similar than in the general population, the similarity of fingerprints of twins is significantly different from that between genuine prints of the same finger. Twins fingerprints are discriminable with a 1.5%~1.7% higher EER than non-twins. And identical twins can be distinguished by examine fingerprint with a slightly higher error rate than fraternal twins.

  4. Dramatically different dizygotic twins: will we include them in Research? Twin research reviews: congenital anomalies, mirror-image effects in conjoined twins, older mothers of twins; Twin statistics: 'Massachusetts, land of twins'; Tribute: Dr Victor A. McKusick.

    Science.gov (United States)

    Segal, Nancy L

    2008-10-01

    The increased frequency of interracial marriage is a likely source of unusual-looking dizygotic (DZ) twins. Some members of DZ twin pairs born to mixed-race couples inherit very different physical features from their parents. This raises several questions, such as: Will researchers wish to include such twins in their ongoing studies? Next, new twin research concerned with congenital anomalies, mirror-image effects in conjoined twins and older mothers of twins will be reviewed. New statistics on twinning rates in Massachusetts will also be summarized, followed by a tribute to the late medical geneticist Dr. Victor A. McKusick.

  5. From near-field to far-field coupling in the third dimension: retarded interaction of particle plasmons.

    Science.gov (United States)

    Taubert, Richard; Ameling, Ralf; Weiss, Thomas; Christ, André; Giessen, Harald

    2011-10-12

    We study the transition from the near-field to the far-field coupling regime of particle plasmons in a three-dimensional geometry. In the far-field regime, retardation plays the dominant role and the plasmonic resonances are radiatively coupled. When the spatial arrangement of the oscillators is matched to their resonance wavelength, superradiant-like effects are observed.

  6. Experimental Verification of the Spectral Shift between Near- and Far-Field Peak Intensities of Plasmonic Nanoantennas

    CERN Document Server

    Alonso-Gonzalez, P; Neubrech, F; Huck, Christian; Chen, J; Golmar, F; Casanova, F; Hueso, L E; Pucci, A; Aizpurua, J; Hillenbrand, R

    2013-01-01

    Theory predicts a distinct spectral shift between the near- and far-field optical responses of plasmonic antennas. Here we combine near-field optical microscopy and far-field spectroscopy of individual infrared-resonant nanoantennas to verify experimentally this spectral shift. Numerical calculations corroborate our experimental results. We furthermore discuss the implications of this effect in surface-enhanced infrared spectroscopy (SEIRS).

  7. [Hereditary phaeochromocytoma in twins].

    Science.gov (United States)

    Tóth, Géza; Patócs, Attila; Tóth, Miklós

    2016-08-01

    Phaeochromocytoma is a tumor of the catecholamine-producing cells of the adrenal gland. Extraadrenal phaeochromocytomas are frequently called paragangliomas. The majority of phaeochromocytomas are sporadic, however, about 25-30% are caused by genetic mutation. These tumor are frequently referred as hereditary phaeochromocytomas/paragangliomas. Their incidence increases continuously which can be attributed to availability of genetic examination and to the discovery of novel genes. The 47-year-old female patient underwent abdominal computed tomography which revealed bilateral adrenal gland enlargement. Abdominal magnetic resonance imaging, the 131-I- metaiodobenzylguanidine scintigraphy, urinary catecholamines and serum chomogranin A measurements confirmed the diagnosis of bilateral phaeochromocytomas. The genetically identical twin sister of the patient was also diagnosed with hormonally active bilateral phaechromocytoma, suggesting the genetic origin of phaeochromocytoma. Mutation screening confirmed a germline mutation of the transmembrane protein 127 tumorsupressor gene in both patients. Both patients underwent cortical-sparing adrenalectomy. The adrenal gland with the larger tumor was totally resected, while in the opposite side only the tumor was resected and a small part of the cortex was saved. After the operation urinary catecholamines and serum chromogranin A returned to normal in both patients. Adrenocortical deficiency was absent in the first patient, but her sister developed adrenal insufficiency requiring glucocorticoid replacement. To the best of the authors' knowledge phaeochromocytoma affecting twins has never been described earlier. Genetic examination performed in siblings confirmed the presence of the mutant gene through four generations. Orv. Hetil., 2016, 157(33), 1326-1330.

  8. Far-Field Emission Pattern of a Dielectric Circular Microresonator with a Point Scatterer

    NARCIS (Netherlands)

    Dettmann, C.P.; Morozov, G.V.; Sieber, M.; Waalkens, H.

    2008-01-01

    The far-field emission pattern of a two-dimensional circular microresonator with a point scatterer inside, at some distance away from the centre, is investigated theoretically. We demonstrate that the presence of the scatterer leads to significant enhancement in the directionality of the outgoing li

  9. Analysis of atrial sensed far-field ventricular signals : A reassessment

    NARCIS (Netherlands)

    Brouwer, J; Nagelkerke, D; denHeijer, P; Mulder, H; Begemann, MJS; Lie, KI; Ruiter, Jaap H.

    1997-01-01

    Accurate detection of the spontaneous far-field ventricular signal may be used to determine the ventricular activation, and hence, the interval from atrial stimulus to the ventricular R wave (AR interval) using a standard atrial pacing lead. This can be useful in developing a physiological atrial ra

  10. Second-order spatial correlation in the far-field: Comparing entangled and classical light sources

    Science.gov (United States)

    Zhang, Erfeng; Liu, Weitao; Lin, Huizu; Chen, Pingxing

    2016-02-01

    We consider second-order spatial correlation with entangled and classical light in the far-field. The quantum theory of second-order spatial correlation is analyzed, and the role of photon statistics and detection mode in the second-order spatial correlation are discussed. Meanwhile, the difference of second-order spatial correlation with entangled and classical light sources is deduced.

  11. Anomalous spectral shift of near- and far-field plasmonic resonances in nano-gaps

    CERN Document Server

    Lombardi, Anna; Weller, Lee; Andrae, Patrick; Benz, Felix; Chikkaraddy, Rohit; Aizpurua, Javier; Baumberg, Jeremy J

    2016-01-01

    The near-field and far-field spectral response of plasmonic systems are often assumed to be identical, due to the lack of methods that can directly compare and correlate both responses under similar environmental conditions. We develop a widely-tuneable optical technique to probe the near-field resonances within individual plasmonic nanostructures that can be directly compared to the corresponding far-field response. In tightly-coupled nanoparticle-on-mirror constructs with nanometer-sized gaps we find >40meV blueshifts of the near-field compared to the dark-field scattering peak, which agrees with full electromagnetic simulations. Using a transformation optics approach, we show such shifts arise from the different spectral interference between different gap modes in the near- and far-field. The control and tuning of near-field and far-field responses demonstrated here is of paramount importance in the design of optical nanostructures for field-enhanced spectroscopy, as well as to control near-field activity ...

  12. Spatially resolved surface topography retrieved from far-field intensity scattering measurements.

    Science.gov (United States)

    Zerrad, Myriam; Lequime, Michel; Amra, Claude

    2014-02-01

    A far-field setup based on the fast and simultaneous recording of 1 million intensity angle-resolved-light-scattering patterns allows both to reconstruct surface topography and to cancel local defects in this topography. A spectral analysis is performed on measured data and allows to extract roughness and slopes mapping of a surface taking into account the spectral bandpass.

  13. Far-field DOA estimation and near-field localization for multipath signals

    Science.gov (United States)

    Elbir, Ahmet M.; Tuncer, T. Engin

    2014-09-01

    In direction finding and localization applications, multipath signals are important sources of error for parameter estimation. When the antenna array receives multipath reflections which are coherent with the far-field line-of-sight signal, estimating the far- and near-field components becomes an important problem. In this paper, a new method is proposed to estimate the direction-of-arrival (DOA) of the far-field source and to localize its near-field multipaths. Far-field source DOA is estimated using calibration of the antenna array. A near-to-far transformation is proposed for the estimation of the near-field source DOA angles. In order to estimate the near-field range parameters, a compressive sensing approach is presented where a dictionary with near-field sources with different ranges is employed. As a result, the proposed method estimates the far-field and near-field source DOAs as well as the range and the signal amplitudes of the near-field sources. This method is evaluated using close-to-real world data generated by a numerical electromagnetic tool, where the array and transmitter are placed in an irregular terrain and array data are generated using full 3-D propagation model. It is shown that unknown source parameters can be estimated effectively showing the potential of the proposed approach in applications involving high-frequency direction finding and indoor localization.

  14. 14 CFR 417.229 - Far-field overpressure blast effects analysis.

    Science.gov (United States)

    2010-01-01

    ... to potential explosions during launch vehicle flight and demonstrate compliance with the public risk... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.229 Far-field overpressure blast effects analysis. (a) General. A flight safety analysis must establish flight commit...

  15. Twins and Kindergarten Separation: Divergent Beliefs of Principals, Teachers, Parents, and Twins

    Science.gov (United States)

    Gordon, Lynn Melby

    2015-01-01

    Should principals enforce mandatory separation of twins in kindergarten? Do school separation beliefs of principals differ from those of teachers, parents of twins, and twins themselves? This survey questioned 131 elementary principals, 54 kindergarten teachers, 201 parents of twins, and 112 twins. A majority of principals (71%) believed that…

  16. Paternal age and telomere length in twins

    DEFF Research Database (Denmark)

    Hjelmborg, Jacob B; Dalgård, Christine; Mangino, Massimo

    2015-01-01

    . Based on two independent (discovery and replication) twin studies, comprising 889 twin pairs, we show an increase in the resemblance of leukocyte telomere length between dizygotic twins of older fathers, which is not seen in monozygotic twins. This phenomenon might result from a paternal age...

  17. Recipient twin limb ischemia with postnatal onset.

    Science.gov (United States)

    Broadbent, Roland Spencer

    2007-02-01

    After the occurrence of 3 local cases of limb ischemia in newborn twins, we reviewed the literature to investigate this combination systematically. This review reveals a distinct condition: postnatal onset limb ischemia affecting recipient twins in twin-twin transfusion syndrome.

  18. Best Practices for Twin Placement in School

    Science.gov (United States)

    Lacina, Jan

    2012-01-01

    The children's book "Two Is for Twins" celebrates twins and illustrates the many "twos" in a child's world. The uniqueness of twos does not have to mean separate classrooms for twins in child development programs, preschool, or elementary school settings. With recent dramatic increases in the US twin population, how should educators address the…

  19. Best Practices for Twin Placement in School

    Science.gov (United States)

    Lacina, Jan

    2012-01-01

    The children's book "Two Is for Twins" celebrates twins and illustrates the many "twos" in a child's world. The uniqueness of twos does not have to mean separate classrooms for twins in child development programs, preschool, or elementary school settings. With recent dramatic increases in the US twin population, how should educators address the…

  20. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  1. Twin methodology in epigenetic studies.

    Science.gov (United States)

    Tan, Qihua; Christiansen, Lene; von Bornemann Hjelmborg, Jacob; Christensen, Kaare

    2015-01-01

    Since the final decades of the last century, twin studies have made a remarkable contribution to the genetics of human complex traits and diseases. With the recent rapid development in modern biotechnology of high-throughput genetic and genomic analyses, twin modelling is expanding from analysis of diseases to molecular phenotypes in functional genomics especially in epigenetics, a thriving field of research that concerns the environmental regulation of gene expression through DNA methylation, histone modification, microRNA and long non-coding RNA expression, etc. The application of the twin method to molecular phenotypes offers new opportunities to study the genetic (nature) and environmental (nurture) contributions to epigenetic regulation of gene activity during developmental, ageing and disease processes. Besides the classical twin model, the case co-twin design using identical twins discordant for a trait or disease is becoming a popular and powerful design for epigenome-wide association study in linking environmental exposure to differential epigenetic regulation and to disease status while controlling for individual genetic make-up. It can be expected that novel uses of twin methods in epigenetic studies are going to help with efficiently unravelling the genetic and environmental basis of epigenomics in human complex diseases.

  2. The vector-like twin Higgs

    Science.gov (United States)

    Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; Strassler, Matthew

    2016-07-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  3. The Vector-like Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Longhi, Pietro; Strassler, Matthew

    2016-01-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  4. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-01

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties.

  5. Failure of vincristine induce twinning

    Science.gov (United States)

    Binder, M.

    1984-01-01

    Mammalian ova do not contain axes of symmetry from which are derived embryonic axes of symmetry. Mammalian axis determination is an early embryologic event occurring at about the time that monozygous twinning in mice. (Kaufma MH & O'Shea KS, 1978, Nature 276:707) and an attempt was made to reproduce their work in several strains of mice. Over 3200 embryos were examined without any twins being found. To rule out the possibility that vincristine caused twinning plus some lethal malformation (with subsequent resorption of the embryo) the embryos were examined 36-60 hours after vincristine treatment.

  6. Twin-to-twin transfusion syndrome : from placental anastomoses to long-term outcome

    NARCIS (Netherlands)

    Lopriore, Enrico

    2006-01-01

    Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Placental vascular anastomoses, almost invariably present in monochorionic placentas, are the essential anatomical substrate for the devel

  7. Twin-to-twin transfusion syndrome : from placental anastomoses to long-term outcome

    NARCIS (Netherlands)

    Lopriore, Enrico

    2006-01-01

    Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Placental vascular anastomoses, almost invariably present in monochorionic placentas, are the essential anatomical substrate for the

  8. Twin-to-twin transfusion syndrome : from placental anastomoses to long-term outcome

    NARCIS (Netherlands)

    Lopriore, Enrico

    2006-01-01

    Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Placental vascular anastomoses, almost invariably present in monochorionic placentas, are the essential anatomical substrate for the devel

  9. Deployment Instabilities of Lobed-Pumpkin Balloon

    Science.gov (United States)

    Nakashino, Kyoichi

    A lobed-pumpkin balloon, currently being developed in ISAS/JAXA as well as in NASA, is a promising vehicle for long duration scientific observations in the stratosphere. Recent ground and flight experiments, however, have revealed that the balloon has deployment instabilities under certain conditions. In order to overcome the instability problems, a next generation SPB called 'tawara' type balloon has been proposed, in which an additional cylindrical part is appended to the standard lobed-pumpkin balloon. The present study investigates the deployment stability of tawara type SPB in comparison to that of standard lobed-pumpkin SPB through eigenvalue analysis on the basis of finite element methods. Our numerical results show that tawara type SPB enjoys excellent deployment performance over the standard lobed-pumpkin SPBs.

  10. Gelastic seizures involving the left parietal lobe.

    Science.gov (United States)

    Machado, René Andrade; Astencio, Adriana Goicoechea

    2012-01-01

    Gelastic seizures have been described in various epilepsies arising from the temporal or frontal lobes, although the most commonly encountered form is related to the presence of a hypothalamic hamartoma. We describe a patient with gelastic seizures involving the left parietal lobe. Our patient, an 8-year-old girl, underwent interictal video/EEG monitoring and MRI. The seizures consisted of brief staring followed by smiling and laughing. Electroencephalography during the gelastic seizures showed rhythmic spikes and waves in the left parietal lobe. MRI revealed the characteristic features of focal cortical dysplasia. Our findings suggest that the left parietal lobe may actively participate in the particular epileptogenic network generating gelastic seizures. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Simultaneous Intussusception in Monozygotic Twins

    Directory of Open Access Journals (Sweden)

    Mete Kaya

    2014-12-01

    Full Text Available In this case report, it was aimed to present the simultaneously occurring intussusception in the monozygotic twins. In addition to genetic predisposition, environmental factors has been hypothesized to be responsible for the development of the disease.

  12. Discordant Epilepsy in Monozygous Twins

    OpenAIRE

    2001-01-01

    Twelve monozygotic twins, discordant for epilepsy, were analysed for nonhereditary etiological factors by clinical history, MRI, and quantitative brain volume studies at the Brain Research Institute, University of Melbourne, Victoria, Australia.

  13. Deep imaging of Fanaroff-Riley Class I radio galaxies with lobes

    CERN Document Server

    Laing, R A; Bridle, A H; Parma, P; Bondi, M

    2011-01-01

    We present deep, high-resolution imaging of the nearby Fanaroff-Riley Class I (FR I) radio galaxies NGC 193, B2 0206+35, B2 0755+37 and M 84 at frequencies of 4.9 and 1.4 GHz using new and archival multi-configuration observations from the Very Large Array. In addition, we describe lower-resolution observations of B2 0326+39 and a reanalysis of our published images of 3C 296. All of these radio galaxies show twin jets and well-defined lobes or bridges of emission, and we examine the common properties of this class of source. We show detailed images of total intensity, brightness gradient, spectral index, degree of polarization and projected magnetic-field direction. The jet bases are very similar to those in tailed twin-jet sources and show the characteristics of decelerating, relativistic flows. Except on one side of M 84, we find that the jets can be traced at least as far as the ends of the lobes, where they often form structures which we call "caps" with sharp outer brightness gradients. Continuing, but l...

  14. Cephalic Aura after Frontal Lobe Resection

    OpenAIRE

    2014-01-01

    A cephalic aura is a common sensory aura typically seen in frontal lobe epilepsy. The generation mechanism of cephalic aura is not fully understood. It is hypothesized that to generate cephalic aura more extensive cortical areas need to be excited. Here we report a patient who started to have cephalic aura after right frontal lobe resection. MEG showed interictal spike and ictal change during cephalic aura, both of which were distributed on right frontal region, and the latter involved much m...

  15. Hypertensive disorders in twin pregnancy

    OpenAIRE

    Santema, Job; Koppelaar, Elin; Wallenburg, Henk

    1995-01-01

    textabstractObjective: To compare the incidence and severity of pregnancy-induced hypertensive disorders in twin pregnancy and in singleton gestation. Study design: Case-control study in the setting of a University Hospital. Each pregnancy of a consecutive series of 187 twin pregnancies attending the antenatal clinic and booked before a gestational age of 24 weeks was matched for maternal age, parity, and gestational age at delivery with a singleton pregnancy delivered in the same year. Prima...

  16. Plasmonic and Mie scattering control of far-field interference for regular ripple formation on various material substrates.

    Science.gov (United States)

    Obara, Go; Maeda, Naoki; Miyanishi, Tomoya; Terakawa, Mitsuhiro; Nedyalkov, Nikolay N; Obara, Minoru

    2011-09-26

    We present experimental and theoretical results on plasmonic control of far-field interference for regular ripple formation on semiconductor and metal. Experimental observation of interference ripple pattern on Si substrate originating from the gold nanosphere irradiated by femtosecond laser is presented. Gold nanosphere is found to be an origin for ripple formation. Arbitrary intensity ripple patterns are theoretically controllable by depositing desired plasmonic and Mie scattering far-field pattern generators. The plasmonic far-field generation is demonstrated not only by metallic nanostructures but also by the controlled surface structures such as ridge and trench structures on various material substrates.

  17. The Qingdao Twin Registry: a status update.

    Science.gov (United States)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng; Wang, Shaojie; Zhang, Dong; Tan, Qihua; Tian, Xiaocao; Pang, Zengchang

    2013-02-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes using twin modeling and genome-wide association analysis. Cross-cultural collaborative studies have been carried out between China, Denmark, Finland, and US cohorts. Ongoing data collection and analysis for the Qingdao Twin Registry will be discussed in this article.

  18. Far-field mapping of the longitudinal magnetic and electric optical fields

    CERN Document Server

    Ecoffey, C

    2013-01-01

    In this letter, we demonstrate the experimental mapping of the longitudinal magnetic and electric optical fields with a standard scanning microscope that involves a high numerical aperture far-field objective. The imaging concept relies upon the insertion of an azimuthal or a radial polarizer within the detection path of the microscope which acts as an optical electromagnetic filter aimed at transmitting selectively to the detector the signal from the magnetic or electric longitudinal fields present in the detection volume, respectively. The resulting system is thus versatile, non invasive, of high resolution, and shows high detection efficiencies. Magnetic optical properties of physical and biological micro and nano-structures may thus be revealed with a far-field microscope.

  19. Analysis of Far-Field Radiation from Apertures Using Monte Carlo Integration Technique

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Fakharian

    2014-12-01

    Full Text Available An integration technique based on the use of Monte Carlo Integration (MCI is proposed for the analysis of the electromagnetic radiation from apertures. The technique that can be applied to the calculation of the aperture antenna radiation patterns is the equivalence principle followed by physical optics, which can then be used to compute far-field antenna radiation patterns. However, this technique is often complex mathematically, because it requires integration over the closed surface. This paper presents an extremely simple formulation to calculate the far-fields from some types of aperture radiators by using MCI technique. The accuracy and effectiveness of this technique are demonstrated in three cases of radiation from the apertures and results are compared with the solutions using FE simulation and Gaussian quadrature rules.

  20. Second-order spatial correlation in the far-field: Comparing entangled and classical light sources

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Erfeng, E-mail: efzhang@163.com; Liu, Weitao; Lin, Huizu; Chen, Pingxing

    2016-02-15

    Highlights: • Second-order spatial correlation with entangled and classical light in the far-field is investigated. • The role of photon statistics and detection mode in the second-order spatial correlation are discussed. • The difference of second-order spatial correlation with entangled and classical light sources is deduced. - Abstract: We consider second-order spatial correlation with entangled and classical light in the far-field. The quantum theory of second-order spatial correlation is analyzed, and the role of photon statistics and detection mode in the second-order spatial correlation are discussed. Meanwhile, the difference of second-order spatial correlation with entangled and classical light sources is deduced.

  1. Far-field subwavelength imaging from a single broadband antenna in combined with strongly disordered medium

    CERN Document Server

    Li, Lianlin; Cui, Tie Jun

    2014-01-01

    The far-field subwavlength imaging is a challenging issue. In this letter we demonstrate numerically that the far-field subwavelength imaging of weakly scattering objects can be obtained by processing the data acquired by a single antenna, which benefits from the use of the strongly disordered medium. A mathematical model has been proposed for solving such problem based on the idea of sparse reconstruction. Moreover, this study leads to an important conclusion that the strongly disordered medium can serves as an efficient apparatus for the single-antenna compressive measurement, which shifts the complexity of devising compressive sensing (CS) hardware from the design, fabrication and electronic control. The proposed method and associated results can find applications in several imaging disciplines, such as optics, THz, RF or ultrasound imaging.

  2. Far-field dispersal modeling for fuel-air-explosive devices

    Energy Technology Data Exchange (ETDEWEB)

    Glass, M.W.

    1990-05-01

    A computer model for simulating the explosive dispersal of a fuel agent in the far-field regime is described and is applied to a wide variety of initial conditions to judge their effect upon the resulting fuel/air cloud. This work was directed toward modeling the dispersal process associated with Fuel-Air-Explosives devices. The far-field dispersal regime is taken to be that time after the initial burster charge detonation in which the shock forces no longer dominate the flow field and initial canister and fuel mass breakup has occurred. The model was applied to a low vapor pressure fuel, a high vapor pressure fuel and a solid fuel. A strong dependence of the final cloud characteristics upon the initial droplet size distribution was demonstrated. The predicted fuel-air clouds were highly non-uniform in concentration. 18 refs., 86 figs., 4 tabs.

  3. Far-Field Turbulent Vortex-Wake/Exhaust Plume Interaction for Subsonic and HSCT Airplanes

    Science.gov (United States)

    Kandil, Osama A.; Adam, Ihab; Wong, Tin-Chee

    1996-01-01

    Computational study of the far-field turbulent vortex-wake/exhaust plume interaction for subsonic and high speed civil transport (HSCT) airplanes is carried out. The Reynolds-averaged Navier-Stokes (NS) equations are solved using the implicit, upwind, Roe-flux-differencing, finite-volume scheme. The two-equation shear stress transport model of Menter is implemented with the NS solver for turbulent-flow calculation. For the far-field study, the computations of vortex-wake interaction with the exhaust plume of a single engine of a Boeing 727 wing in a holding condition and two engines of an HSCT in a cruise condition are carried out using overlapping zonal method for several miles downstream. These results are obtained using the computer code FTNS3D. The results of the subsonic flow of this code are compared with those of a parabolized NS solver known as the UNIWAKE code.

  4. Multi-pulse pumping for far-field super-resolution imaging

    Science.gov (United States)

    Requena, Sebastian; Raut, Sangram; Doan, Hung; Kimball, Joe; Fudala, Rafal; Borejdo, Julian; Gryczynski, Ignacy; Strzhemechny, Yuri; Gryczynski, Zygmunt

    2016-02-01

    Recently, far-field optical imaging with a resolution significantly beyond diffraction limit has attracted tremendous attention allowing for high resolution imaging in living objects. Various methods have been proposed that are divided in to two basic approaches; deterministic super-resolution like STED or RESOLFT and stochastic super-resolution like PALM or STORM. We propose to achieve super-resolution in far-field fluorescence imaging by the use of controllable (on-demand) bursts of pulses that can change the fluorescence signal of long-lived component over one order of magnitude. We demonstrate that two beads, one labeled with a long-lived dye and another with a short-lived dye, separated by a distance lower than 100 nm can be easily resolved in a single experiment. The proposed method can be used to separate two biological structures in a cell by targeting them with two antibodies labeled with long-lived and short-lived fluorophores.

  5. Examination of Far-Field Mathematical Absorber Reflection Suppression through Computational Electromagnetic Simulation

    Directory of Open Access Journals (Sweden)

    S. F. Gregson

    2012-01-01

    Full Text Available The mathematical absorber reflection suppression (MARS technique has been used to identify and then suppress the effects of spurious scattering within spherical, cylindrical, and planar near-field antenna measurement systems, compact antenna test ranges (CATRs, and far-field measurement facilities for some time now. The recent development of a general-purpose three-dimensional computational electromagnetic model of a spherical antenna test system has enabled the MARS measurement and postprocessing technique to be further investigated. This paper provides an overview of the far-field MARS technique and presents an introduction to the computational electromagnetic range model. Preliminary results of computational electromagnetic range simulations that replicate typical MARS measurement configurations are presented and discussed which, for the first time, confirm through simulation many of the observations that have previously been noted using purely empirical techniques.

  6. Concept of far-field optical evaluation of the apparatus function of an SNOM tip

    Science.gov (United States)

    Voznesensky, Nikolay B.; Veiko, Vadim P.; Ivanova, Tatiana V.; Lee, Kyeong-Hee

    2004-04-01

    An approach to the optical investigation of probes for scanning near-field optical microscopes (SNOM tips) and recognition of their near-field parameters by far-field measurements is considered. The comparison of approximate calculations of vector light field diffracted by a subwavelength aperture with more rigorous calculations of the light field passing through a tapered end of a SNOM tip is presented. A numerical iterative procedure of the SNOM tip aperture reconstruction by the analytical continuation of the emerging light Fourier spectrum is presented. The approach is based on the use of plane waves covering a wide range of spatial frequencies. The results of experimental measurements and far-field data treatment with the definition of a subwavelength aperture are discussed.

  7. A Coupled Far-Field Formulation for Time-Periodic Numerical Problems in Fluid Dynamics

    Indian Academy of Sciences (India)

    Edmund Chadwick; Rabea El-Mazuzi

    2012-11-01

    Consider uniform flow past an oscillating body generating a time-periodic motion in an exterior domain, modelled by a numerical fluid dynamics solver in the near field around the body. A far-field formulation, based on the Oseen equations, is presented for coupling onto this domain thereby enabling the whole space to be modelled. In particular, examples for formulations by boundary elements and infinite elements are described.

  8. Chiral-field microwave antennas (Chiral microwave near fields for far-field radiation)

    CERN Document Server

    Kamenetskii, E O; Shavit, R

    2015-01-01

    In a single-element structure we obtain a radiation pattern with a squint due to chiral microwave near fields originated from a magnetostatic-mode ferrite disk. At the magnetostatic resonances, one has strong subwavelength localization of energy of microwave radiation. Magnetostatic oscillations in a thin ferrite disk are characterized by unique topological properties: the Poynting-vector vortices and the field helicity. The chiral-topology near fields allow obtaining unique phase structure distribution for far-field microwave radiation.

  9. Optical far-field super-resolution microscopy using nitrogen vacancy center ensemble in bulk diamond

    OpenAIRE

    Li, Shen; Chen, Xiang-Dong; Zhao, Bo-Wen; Dong, Yang; Zou, Chong-Wen; Guo, Guang-Can; Sun, Fang-Wen

    2016-01-01

    We demonstrate an optical far-field super-resolution microscopy using array of nitrogen vacancy centers in bulk diamond as near-field optical probes. The local optical field, which transmits through the nanostructures on the diamond surface, is measured by detecting the charge state conversion of nitrogen vacancy center. And the locating of nitrogen vacancy center with spatial resolution of 6.1 nm is realized with the charge state depletion nanoscopy. The nanostructures on the surface of diam...

  10. Note on the classification of super-resolution in far-field microscopy and information theory

    CERN Document Server

    Passon, Oliver

    2016-01-01

    In recent years several far-field microscopy techniques have been developed which manage to overcome the diffraction limit of resolution. A unifying classification scheme for them is clearly desirable. We argue that existing schemes based on the information capacity of the optical system can not easily be extended to cover e.g., STED microscopy or techniques based on single molecule imaging. We suggest a classification based on a reconstruction of the Abbe limit.

  11. Far-field momentum flux of high-frequency axisymmetric synthetic jets

    Science.gov (United States)

    Xia, X.; Mohseni, K.

    2015-11-01

    This study focuses on predicting the far-field momentum flux for axisymmetric synthetic jets, which is an important parameter that characterizes the performance of such jets in flow-control applications. Previous researchers have found that a negative pressure gradient near the jet orifice is responsible for the observed decrease in the momentum flux in the streamwise direction. As a result, prediction of the far field momentum flux of synthetic jets has encountered serious challenges. In this paper, the far-field momentum flux is modeled by calculating the hydrodynamic impulse of the vortical structure formed during one actuation cycle, under the assumption that the jet is fully developed and periodic. In this manner, the complex near-field effect of a synthetic jet is explicitly captured by the interactions between the vortices and the actuator. Furthermore, the impulse of these vortical structures is predicted using only the actuation parameters of the synthetic jet, namely, the stroke length, L, the orifice diameter, d, and the actuation frequency, f. For a synthetic jet with a stroke ratio, L/d, larger than the formation number, L∗/d, this model predicts that the normalized far-field momentum flux, K/Ks, decreases when L/d increases. This can be explained by an increasing circulation fraction of the trailing jet, which contains less impulse per unit circulation compared with the leading vortex. This model is validated using hot-wire anemometry measurement of a series of synthetic jets. Moreover, by comparing with experimental data that have large L/d, this model suggests that the contribution of trailing jet to the overall far-field momentum flux is not negligible.

  12. Note on the classification of super-resolution in far-field microscopy and information theory

    Science.gov (United States)

    Passon, Oliver; Grebe-Ellis, Johannes

    2016-07-01

    In recent years several far-field microscopy techniques have been developed which manage to overcome the diffraction limit of resolution. A unifying classification scheme for them is clearly desirable. We argue that existing schemes based on the information capacity of the optical system can not easily be extended to cover e.g., STED microscopy or techniques based on single molecule imaging. We suggest a classification based on a reconstruction of the Abbe limit.

  13. Estimating twin concordance for bivariate competing risks twin data.

    Science.gov (United States)

    Scheike, Thomas H; Holst, Klaus K; Hjelmborg, Jacob B

    2014-03-30

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experienced the event of interest. Under the assumption that both twins are censored at the same time, we show how to estimate this probability in the presence of right censoring, and as a consequence, we can then estimate the casewise twin concordance. In addition, we can model the magnitude of within pair dependence over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer events with the competing risk death. We thus aim to quantify the degree of dependence through the casewise concordance function and show a significant genetic component.

  14. Spina bifida occulta and monozygotic twins.

    Science.gov (United States)

    Spacca, Barbara; Buxton, Neil

    2008-10-01

    Central nervous system maldevelopment can have different presentations in twins. We report on a case of different presentations of spina bifida occulta in monozygotic twins. The first twin presented at birth with a lipomyelomeningocele; a tethered cord was diagnosed in the second twin at 2 years of age. Neural tube defects (NTDs) are a group of common congenital malformations of the brain and spine generated during neurulation. The genetic basis of this process is still not well known. Whenever an NTD is diagnosed in one of a pair of twins, the other twin should also be evaluated for NTDs.

  15. [Twin dystocia: about one case of compaction].

    Science.gov (United States)

    Desseauve, D; Voluménie, J-L

    2008-09-01

    We report a case of twin dystocia during the evacuation of full-term fetus both in cephalic presentation. A low-outlet forceps for second-phase arrest was performed for the first twin but the head remained stuck to maternal perineum, mimicking a shoulder dystocia. Digital examination found a twin compaction, that is the presence of the second twin's fetal head at the level of the first twin's chest. The discrepancy between fetal weights and the use of forceps could favor this rare complication. Various maneuvers were described previously attempted to solve the problem. Forcing back the second head may help to achieve delivery of the first twin.

  16. [The Chinese national twin cohort: an update].

    Science.gov (United States)

    Gao, W J; Li, L M

    2017-06-10

    The importance of large cohort studies in China has been increasingly emphasized. As special group in the population, twins provide excellent natural resources since they share the same birthday, maternal intrauterine environment and early family environment. Twin cohorts are unique for and benefit on controlling the confounding factors as age, gender (same-sex twins), genetic background (monozygotic twins) or early environment (being raised together) in the etiological studies on complex diseases. In this review, we briefly introduce the objectives, current situation, challenges and opportunities related to the Chinese national twin cohort, focusing on the characteristics of twins that are different from other groups in the general population.

  17. TWIN GESTATION : A CHALLENGING TASK

    Directory of Open Access Journals (Sweden)

    Vrunda V.

    2015-03-01

    Full Text Available INTRODUCTION In the era of modern obstetrics when multiple pregnancies are on increase it is very important to know the incidence and obstetric outcomes of twin deliveries. Twin pregnancy is still associated with increased maternal and perinatal morbidity and mortality as well as healthcare costs . ( 1 , 2 , 3 MATERIALS AND METHODS : This is a r etrospective study of twin deliveries done in the rural medical college teaching hospital over a period of 3 years. RESULTS : During the study period , incidence of twin delivery was 19.37 per 1000 deliveries. Majority cases of twins were young primies in ag e group (20 - 30 years . Preterm delivery occurred in 68% cases and was therefore , the most common morbidity followed by anaemia (38% and PIH (28%. Most common presentation was vertex (66% and malpresentation were present in 44% of cases. 54% were deliver ed by caesarean section. In 88% second baby delivered within 15 minutes. Uterine inertia , PROM , fetal distress , PPH , cord prolapse and abruption were complications during labour. There was no maternal mortality in present study. Average weight of first baby was 1679.63 gms and 2 nd baby was 1586.94 gms. Perinatal mortality of 1 st baby was 27.55 for 1 st baby and 37.25% for 2 nd baby . Average gestational age for patients in whom cervical encirclage was done was 34 weeks. CONCLUSION: P reterm delivery and low birth weight babies are main challenges to the obstetrician. Incidence of LSCS is quite high with malpresentation of leading (twin A baby is a major indication for LSCS . The use of antenatal care services and good intrapartum mana gement will help improve outcome in twin pregnancies.

  18. Far-field optical imaging with subdiffraction resolution enabled by nonlinear saturation absorption

    Science.gov (United States)

    Ding, Chenliang; Wei, Jingsong

    2016-01-01

    The resolution of far-field optical imaging is required to improve beyond the Abbe limit to the subdiffraction or even the nanoscale. In this work, inspired by scanning electronic microscopy (SEM) imaging, in which carbon (or Au) thin films are usually required to be coated on the sample surface before imaging to remove the charging effect while imaging by electrons. We propose a saturation-absorption-induced far-field super-resolution optical imaging method (SAI-SRIM). In the SAI-SRIM, the carbon (or Au) layers in SEM imaging are replaced by nonlinear-saturation-absorption (NSA) thin films, which are directly coated onto the sample surfaces using advanced thin film deposition techniques. The surface fluctuant morphologies are replicated to the NSA thin films, accordingly. The coated sample surfaces are then imaged using conventional laser scanning microscopy. Consequently, the imaging resolution is greatly improved, and subdiffraction-resolved optical images are obtained theoretically and experimentally. The SAI-SRIM provides an effective and easy way to achieve far-field super-resolution optical imaging for sample surfaces with geometric fluctuant morphology characteristics.

  19. The spectral shift between near- and far-field resonances of optical nano-antennas.

    Science.gov (United States)

    Menzel, Christoph; Hebestreit, Erik; Mühlig, Stefan; Rockstuhl, Carsten; Burger, Sven; Lederer, Falk; Pertsch, Thomas

    2014-04-21

    Within the past several years a tremendous progress regarding optical nano-antennas could be witnessed. It is one purpose of optical nano-antennas to resonantly enhance light-matter interactions at the nanoscale, e.g. the interaction of an external illumination with molecules. In this specific, but in almost all schemes that take advantage of resonantly enhanced electromagnetic fields in the vicinity of nano-antennas, the precise knowledge of the spectral position of resonances is of paramount importance to fully exploit their beneficial effects. Thus far, however, many nano-antennas were only optimized with respect to their far-field characteristics, i.e. in terms of their scattering or extinction cross sections. Although being an emerging feature in many numerical simulations, it was only recently fully appreciated that there exists a subtle but very important difference in the spectral position of resonances in the near-and the far-field. With the purpose to quantify this shift, Zuloaga et al. suggested a Lorentzian model to estimate the resonance shift. Here, we devise on fully analytical grounds a strategy to predict the resonance in the near-field directly from that in the far-field and disclose that the issue is involved and multifaceted, in general. We outline the limitations of our theory if more sophisticated optical nano-antennas are considered where higher order multipolar contributions and higher order antenna resonances become increasingly important. Both aspects are highlighted by numerically studying relevant nano-antennas.

  20. Fluorescent Nanowire Ring Illumination for Wide-Field Far-Field Subdiffraction Imaging

    Science.gov (United States)

    Liu, Xiaowei; Kuang, Cuifang; Hao, Xiang; Pang, Chenlei; Xu, Pengfei; Li, Haifeng; Liu, Ying; Yu, Chao; Xu, Yingke; Nan, Di; Shen, Weidong; Fang, Yue; He, Lenian; Liu, Xu; Yang, Qing

    2017-02-01

    Here we demonstrate an active method which pioneers in utilizing a combination of a spatial frequency shift and a Stokes frequency shift to enable wide-field far-field subdiffraction imaging. A fluorescent nanowire ring acts as a localized source and is combined with a film waveguide to produce omnidirectional illuminating evanescent waves. Benefitting from the high wave vector of illumination, the high spatial frequencies of an object can be shifted to the passband of a conventional imaging system, contributing subwavelength spatial information to the far-field image. A structure featuring 70-nm-wide slots spaced 70 nm apart has been resolved at a wavelength of 520 nm with a 0.85 numerical aperture standard objective based on this method. The versatility of this approach has been demonstrated by imaging integrated chips, Blu-ray DVDs, biological cells, and various subwavelength 2D patterns, with a viewing area of up to 1 0 0 0 μ m2 , which is one order of magnitude larger than the previous far-field and full-field nanoscopy methods. This new resolving technique is label-free, is conveniently integrated with conventional microscopes, and can potentially become an important tool in cellular biology, the on-chip industry, as well as other fields requiring wide-field nanoscale visualization.

  1. Twin-twin transfusion syndrome: neurodevelopmental screening test

    Directory of Open Access Journals (Sweden)

    Amabile Vessoni Arias

    2015-03-01

    Full Text Available Objective To assess the neurodevelopmental functions (cognition, language and motor function of survivors of twin-twin transfusion syndrome (TTTS. Method Observational cross-sectional study of a total of 67 monochorionic diamniotic twins who underwent fetoscopic laser coagulation (FLC for treatment of TTTS. The study was conducted at the Center for Investigation in Pediatrics (CIPED, Universidade Estadual de Campinas. Ages ranged from one month and four days to two years four months. Bayley Scales of Infant and Toddler Development Screening Test-III, were used for evaluation. Results Most children reached the competent category and were classified as having appropriate performance. The preterm children scored worse than term infants for gross motor subtest (p = 0.036. Conclusion The majority of children reached the expected development according to their age. Despite the good neurodevelopment, children classified at risk should be monitored for development throughout childhood.

  2. Femtosecond refractive-index tailoring of an optical fiber and phase retrieval from far-field measurements

    DEFF Research Database (Denmark)

    Savolainen, Juha-Matti; Grüner-Nielsen, Lars; Kristensen, Poul

    2013-01-01

    A refractive-index change is written inside an optical fiber close to the end face by femtosecond laser light. The induced phase change is measured by analyzing the far-field intensity profiles before and after the irradiation.......A refractive-index change is written inside an optical fiber close to the end face by femtosecond laser light. The induced phase change is measured by analyzing the far-field intensity profiles before and after the irradiation....

  3. Realization of periodic and quasiperiodic microstructures with sub-diffraction-limit feature sizes by far-field holographic lithography

    Science.gov (United States)

    Yang, Yi; Wang, Guo Ping

    2006-09-01

    The authors experimentally demonstrate a far-field holography for the realization of Ag nanoparticles-embedded periodic and quasiperiodic microstructures with feature sizes beyond the diffraction limit. Periodic cylindrical nanoshell arrays with about 240nm hole diameter and 12-fold symmetry quasiperiodic structures with 220nm feature sizes are achieved, respectively, by using a 632.8nm laser beam. Our results imply that conventional far-field optical technology is capable of fabricating nanostructures in modern micromanufacture.

  4. Femtosecond refractive-index tailoring of an optical fiber and phase retrieval from far-field measurements

    DEFF Research Database (Denmark)

    Savolainen, Juha-Matti; Grüner-Nielsen, Lars; Kristensen, Poul;

    2013-01-01

    A refractive-index change is written inside an optical fiber close to the end face by femtosecond laser light. The induced phase change is measured by analyzing the far-field intensity profiles before and after the irradiation.......A refractive-index change is written inside an optical fiber close to the end face by femtosecond laser light. The induced phase change is measured by analyzing the far-field intensity profiles before and after the irradiation....

  5. Fornax A's Western Radio Lobe Composition

    Science.gov (United States)

    Kong, Jason J.; Nulsen, P. E. J.; Kraft, R. P.

    2011-01-01

    We present an analysis of the western radio lobe of Fornax A based on an XMM-Newton observation. We find little evidence for the inverse-Compton scattering of the cosmic microwave background as reported previously. The spectra in the energy range of 0.5-5 keV are well fitted by a thermal plus power law model for every spectral region we extracted. With a fixed photon index of 1.68, the X-ray flux density at 1 keV from the power law fit was measured to be cool gas extends from the central galaxy in the direction of the radio lobe of Fornax A. Spectral fits give a temperature of kT=0.76 keV over the radio lobe and kT=0.32 keV for the cool filament. The thermal emission from the radio lobe region is best explained as emission from a thin shell of shocked gas swept up by the rapidly expanding lobe. This work is supported in part by the NSF REU and DOD ASSURE programs under NSF grant no. 0754568 and by the Smithsonian Institution.

  6. Effect of lobe profile on the load capacity of 2-lobe journal bearing

    Institute of Scientific and Technical Information of China (English)

    Stanislaw; STRZELECKI

    2001-01-01

    The rotors of turbogenerators operate in 2-lobe journal bearings. These bearings can bedesigned with the same or different profile of upper and bottom lobe, e.g. the upper lobe has cylin-drical and bottom one the offset profile. Shaping the bearing profile this way allows the variation ofstatic and dynamic characteristics of bearing. The static characteristics consist among others theload capacity of bearing which is very important parameter. The paper introduces the results ofcalculations of load capacity of 2-lobe journal bearing characterised by different profiles of upperand bottom lobe. The laminar, adiabatic oil flow in the bearing lubricating gap, parallel orientationof journal and bearing axis as well as the static equilibrium position of journal have been assumed.

  7. TWIN PREGNANCY WITH ACARDIUS ANCEPS

    Directory of Open Access Journals (Sweden)

    Padma

    2014-02-01

    Full Text Available Acardiac twin is an anomaly unique to monochorionic multiple pregnancies, characterized by formation of malformed fetus with an absent or rudimentary (nonfunctional heart. Acardiac twinning, often results from abnormal placental vascular anastomoses. A 20 year old primigravida admitted to the department of Obstetrics and Gynecology S .S. Medical College, Rewa, on 26th July 2012 at the gestation of 34 week with spontaneous monochorionic monoamniotic twin pregnancy and fetal acardius with oligohydramnios. Patient was taking her treatment from private Hospital; acardius was diagnosed at 27 week due to late booking. In view of oligohydramnios and hypoxic changes in color Doppler, elective LSCS was done on 28/7/13 at 34 week 2 day, after betnesol coverage. She delivered a live, healthy, female child with good APGAR score having apparently no congenital anomaly, with a birth weight of 2.3 kg .The other twin was fetus acardius, of about900 gm. with head and face partially developed . Upper limb was rudimentary and lower limb was partially developed and malformed. External genitalia were developed as female. Placenta was monochorionic and monoamniotic, weighing500 gm. The umbilical cord of the normal twin was20 cm with central attachment, while the other umbilical cord was10 cm long with peripheral attachment

  8. TwinMux Testing System

    CERN Document Server

    Wong, Wei Wen; CERN. Geneva. PH Department

    2015-01-01

    During the CERN summer school program, I joined the CMS Muon Drift Tube (DT) group, and mainly worked on two projects, which, both of them, are related to the electronics of a new data concentrator called the “TwinMux”. My first task within the TwinMux project was to build an integrated software test station in order to run several tests on the functionality of the TwinMux hardware. Essentially, I had to integrate existing testing scripts, adding several new ones, into a single user-friendly testing platform which can perform quick, convenient and automated hardware testing. Later, I was also involved in the design of the local technical triggering of the DT. Such system relies on some firmware functionality built in the TwinMux and controlled by software. I had attempted two different approaches to design the communication topology of all the 12 TwinMux cards in order to send a user-defined logical operation to the read-out electronics. The final goal of this system is to drive local trigger signal for...

  9. Complications arising in twin pregnancy: findings of prenatal ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Ah; Cho, Jeong Yeon; Lee, Young Ho; Song, Mi Jin; Min, Jee Yeon; Lee, Hak Jong; Han, Byoung Hee; Lee, Kyung Sang; Cho, Byung Jae; Chun, Yi Kyeong [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2003-03-01

    Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios- polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications.

  10. Breast-Feeding Twins: Making Feedings Manageable

    Science.gov (United States)

    ... more than one baby? Here's help breast-feeding twins or other multiples, from getting positioned and ensuring ... babies who are born prematurely, as are many twins and higher order multiples. Breast milk is easier ...

  11. Risk of Oral Clefts in Twins

    DEFF Research Database (Denmark)

    Grosen, Dorthe; Bille, Camilla; Petersen, Inge

    2011-01-01

    BACKGROUND:: Small studies have indicated that twinning increases the risk of oral cleft. METHODS:: We used data from a Danish national population-based cohort study to investigate whether twinning was associated with isolated oral cleft, and to estimate the twin probandwise concordance rate...... and heritability. Twins (207 affected/130,710) and singletons (7766 affected/4,798,526) born from 1936 through 2004 in Denmark were ascertained by linkage among the Danish Facial Cleft Database, the Danish Twin Registry, and the Civil Registration System. We computed oral cleft prevalence and prevalence proportion...... ratio for twins versus singletons, stratified for 3 subphenotypes. Probandwise concordance rates and heritability for twins were estimated for 2 phenotypes-cleft lip with or without cleft palate (CL/P) and cleft palate (CP). RESULTS:: The prevalence of oral cleft was 15.8 per 10,000 twins and 16.6 per...

  12. Having Twins? How to Stay Healthy

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Having Twins? How to Stay Healthy Page Content Article Body ... the eyes of obstetricians. Many would call a twin pregnancy a high-risk pregnancy , but don’t ...

  13. Nike Twins Seven Seven: Nigerian Batik Artist.

    Science.gov (United States)

    LaDuke, Betty

    1987-01-01

    Chronicles the personal and professional life of Nike Twins Seven Seven (born 1951), a Nigerian batik artist, and her husband, Twins Seven Seven, a musician-artist, both of whom have received international acclaim. (BJV)

  14. Preterm twin gestation and cystic periventricular leucomalacia

    NARCIS (Netherlands)

    Resch, B; Jammernegg, A; Vollaard, E; Maurer, U; Mueller, WD; Pertl, B

    2004-01-01

    Objective: To identify risk factors for the development of cystic periventricular leucomalacia (PVL) in twin gestation. Design: Retrospective case-control study. Setting: Tertiary care university hospital, Department of Paediatrics, Division of Neonatology, Graz, Austria. Patients: Preterm twin gest

  15. Nike Twins Seven Seven: Nigerian Batik Artist.

    Science.gov (United States)

    LaDuke, Betty

    1987-01-01

    Chronicles the personal and professional life of Nike Twins Seven Seven (born 1951), a Nigerian batik artist, and her husband, Twins Seven Seven, a musician-artist, both of whom have received international acclaim. (BJV)

  16. Learning and memory in monozygotic twins discordant for schizophrenia.

    Science.gov (United States)

    Goldberg, T E; Torrey, E F; Gold, J M; Ragland, J D; Bigelow, L B; Weinberger, D R

    1993-02-01

    Learning and memory were assessed in 24 monozygotic (MZ) pairs of individuals discordant for schizophrenia or delusional disorder and seven normal pairs of MZ twins. On declarative memory tasks, the affected group displayed a pattern that might best be characterized as dysmnesic in that they performed significantly worse than the discordant unaffected group on story recall, paired associated learning, and visual recall of designs, but they learned over time, had relatively preserved recognition memory, and did not show profoundly accelerated rates of forgetting. Effortful, volitional retrieval from the lexicon, measured by verbal fluency, was also compromised in the affected group. On the other hand, procedural learning of the motor skill in a pursuit rotor task was relatively intact in the affected group. Comparisons of the normal group and unaffected group indicated that the latter group had very mild impairments in some aspects of episodic memory, namely, immediate and delayed recall of stories and delayed recall of designs. It is highly unlikely that the impairments observed in the affected group can be attributed to differences in genome, family environment, socioeconomic circumstance, or educational opportunity, as all of these were controlled by the twin paradigm. Rather, the impairments appear to be related to the intercession of disease. The neuropsychological profile is consistent with frontal lobe and medial temporal lobe dysfunction, as noted in this sample as well as other samples of schizophrenic singletons. Significant correlations between many measures of memory and global level of social and vocational functioning within the discordant group were also found. Thus difficulties in rapidly acquiring new information and propitiously retrieving old information may burden patients with schizophrenia in many of the transactions of everyday life.

  17. Medical image of the week: azygous lobe

    Directory of Open Access Journals (Sweden)

    Bhupinder Natt

    2013-12-01

    Full Text Available No abstract available. Article truncated at 150 words. A 59 year old man underwent chest radiography for evaluation of fever and cough. Imaging showed an accessory azygous lobe. An azygos lobe is found in 1% of anatomic specimens and forms when the right posterior cardinal vein, one of the precursors of the azygos vein, fails to migrate over the apex of the lung (1. Instead, the vein penetrates the lung carrying along pleural layers that entrap a portion of the right upper lobe. The vein appears to run within the lung, but is actually surrounded by both parietal and visceral pleura. The azygos fissure therefore consists of four layers of pleura, two parietal layers and two visceral layers, which wrap around the vein giving the appearance of a tadpole. Apart from an interesting incidental radiological finding, it is of limited clinical importance except that its presence should be recognized during thoracoscopic procedures. This patient was found to have …

  18. Dementia of Frontal Lobe Type and Amyotrophy

    Directory of Open Access Journals (Sweden)

    I. Ferrer

    1992-01-01

    Full Text Available Dementia of frontal lobe type may precede motor signs in a number of adult patients with amyotrophy. Neuropathological studies have shown neuron loss, spongiosis and gliosis mainly in layers II and III of the frontal and temporal lobes, together with myelin pallor of the subcortical white matter. Golgi studies revealed loss of dendritic spines on the apical dendrite of layer III pyramidal neurons, decreased numbers of dendrites, amputation and tortuosities of dendrites, and distal and proximal dendritic swellings and enlargements. Calbindin D-28K immunocytochemistry revealed a marked decrease in the number of cortical immunoreactive neurons and loss of immunoreactivity in dendrites of the remaining cells. These features indicate that pyramidal and non-pyramidal neurons in layers II and III are severely damaged, and suggest that cortical processing is seriously impaired in patients with frontal lobe type dementia.

  19. Parietal Lobes in Schizophrenia: Do They Matter?

    Science.gov (United States)

    Yildiz, Murat; Borgwardt, Stefan J.; Berger, Gregor E.

    2011-01-01

    Objective. Despite observations that abnormal parietal lobe (PL) function is associated with psychotic-like experiences, our knowledge about the nature of PL involvement in schizophrenia is modest. The objective of this paper is to investigate the role of the PL in schizophrenia. Method. Medline databases were searched for English language publications using the following key words: parietal lobe, combined with schizophrenia, lesions, epilepsy, cognition, rare genetic disorders, MRI, fMRI, PET, and SPECT, respectively, followed by cross-checking of references. Results. Imaging studies in childhood onset schizophrenia suggest that grey matter abnormalities start in parietal and occipital lobes and proceed to frontal regions. Although, the findings are inconsistent, several studies with patients at risk to develop schizophrenia indicate early changes in the PL. Conclusions. We want to propose that in a proportion of individuals with emerging schizophrenia structural and functional alterations may start in the PL and progress to frontal regions. PMID:22937268

  20. Twins or two single children

    Directory of Open Access Journals (Sweden)

    2002-08-01

    Full Text Available Based on Swedish register data, we compared the influence of a twin birth on the divorce risk with the influence of the sequential birth of two single children. The divorce risk for a woman with a very young child was lower than the risk for women without children or women with children older than 3.5 years. This behaviour was essentially independent of the number of children and whether or not the woman gave birth to twins. The effect of parity was much smaller than the effect of child age. The influence of twins on the divorce risk appeared to fall between that of a first and a second singleton.

  1. Twin TQFTs and Frobenius Algebras

    Directory of Open Access Journals (Sweden)

    Carmen Caprau

    2013-01-01

    Full Text Available We introduce the category of singular 2-dimensional cobordisms and show that it admits a completely algebraic description as the free symmetric monoidal category on a twin Frobenius algebra, by providing a description of this category in terms of generators and relations. A twin Frobenius algebra (C,W,z,z∗ consists of a commutative Frobenius algebra C, a symmetric Frobenius algebra W, and an algebra homomorphism z:C→W with dual z∗:W→C, satisfying some extra conditions. We also introduce a generalized 2-dimensional Topological Quantum Field Theory defined on singular 2-dimensional cobordisms and show that it is equivalent to a twin Frobenius algebra in a symmetric monoidal category.

  2. Twins' injuries: genetic and environmental risks / twin research reports / human interest stories.

    Science.gov (United States)

    Segal, Nancy L

    2011-04-01

    The relative contributions of genetic and environmental factors to unintentional injuries are of interest to families with young twins. A recent study found that childhood injuries are explained mostly by child-specific environmental factors. Next, twin research reviews of the association between periodontal disease and cancer, secular trends in gestational age and birthweight, and language development in hearing and deaf co-twins are also summarized. Interesting reports of newborn twins, twin-like relationships, twin interactions and missed twin relationships are presented.

  3. The Fourth International Network of Twin Registries: Overview from Osaka/Research Reviews: Familial Fraternal Twinning; Twin Study of Masculine Faces; Physical Aggression and Epigenetics; Prenatal Education for Parents of Twins/Current Events: 2016 Guinness Book of World Records; Oldest Living Male Twins; Twins Reunited at Sixty-Nine; Panda Twins; Twins.com.

    Science.gov (United States)

    Segal, Nancy L

    2015-12-01

    The 4th International Network of Twin Registries (INTR) Consortium Meeting took place in Osaka, Japan, September 28-29, 2015. The venue was the Osaka Medical Center for Medical Innovation and Translational Research. An overview of presentations and other activities is provided. Next, 1930s research on familial fraternal twinning, preference for masculine faces, physical aggression and epigenetics, and a prenatal education program for parents of multiples are described. Current twin-related events include the 2016 Guinness Book of World Records (GWR), the oldest living male twins, newly reunited twins, the birth of panda twins and a controversial twin-based website.

  4. Automated MRI parcellation of the frontal lobe.

    Science.gov (United States)

    Ranta, Marin E; Chen, Min; Crocetti, Deana; Prince, Jerry L; Subramaniam, Krish; Fischl, Bruce; Kaufmann, Walter E; Mostofsky, Stewart H

    2014-05-01

    Examination of associations between specific disorders and physical properties of functionally relevant frontal lobe sub-regions is a fundamental goal in neuropsychiatry. Here, we present and evaluate automated methods of frontal lobe parcellation with the programs FreeSurfer(FS) and TOADS-CRUISE(T-C), based on the manual method described in Ranta et al. [2009]: Psychiatry Res 172:147-154 in which sulcal-gyral landmarks were used to manually delimit functionally relevant regions within the frontal lobe: i.e., primary motor cortex, anterior cingulate, deep white matter, premotor cortex regions (supplementary motor complex, frontal eye field, and lateral premotor cortex) and prefrontal cortex (PFC) regions (medial PFC, dorsolateral PFC, inferior PFC, lateral orbitofrontal cortex [OFC] and medial OFC). Dice's coefficient, a measure of overlap, and percent volume difference were used to measure the reliability between manual and automated delineations for each frontal lobe region. For FS, mean Dice's coefficient for all regions was 0.75 and percent volume difference was 21.2%. For T-C the mean Dice's coefficient was 0.77 and the mean percent volume difference for all regions was 20.2%. These results, along with a high degree of agreement between the two automated methods (mean Dice's coefficient = 0.81, percent volume difference = 12.4%) and a proof-of-principle group difference analysis that highlights the consistency and sensitivity of the automated methods, indicate that the automated methods are valid techniques for parcellation of the frontal lobe into functionally relevant sub-regions. Thus, the methodology has the potential to increase efficiency, statistical power and reproducibility for population analyses of neuropsychiatric disorders with hypothesized frontal lobe contributions. Copyright © 2013 Wiley Periodicals, Inc.

  5. Do Twin Boundaries Always Strengthen Metal Nanowires?

    OpenAIRE

    Zhang Yongfeng; Huang Hanchen

    2008-01-01

    Abstract It has been widely reported that twin boundaries strengthen nanowires regardless of their morphology—that is, the strength of nanowires goes up as twin spacing goes down. This article shows that twin boundaries do not always strengthen nanowires. Using classical molecular dynamics simulations, the authors show that whether twin boundaries strengthen nanowires depends on the necessary stress for dislocation nucleation, which in turn depends on surface morphologies. When nanowire...

  6. Twins reunited: scientific and personal perspectives/twin research studies: multiple birth effects on IQ and body size; life style, muscles, and metabolism; monochorionic dizygotic twin with blood chimerism; amniocentesis for twins/twins in the media: identical doctors; freedom fighter for twins; twin scholarships; Auguste and Jean-Felix Piccard; twins born apart.

    Science.gov (United States)

    Segal, Nancy L; Mulligan, Christy A

    2014-04-01

    A reunion of 38-year-old female monozygotic twins took place in Daegu, South Korea, on January 14, 2014. Scientific and personal perspectives on this extraordinary event are provided. A review of timely twin research follows, covering the effects of multiple births on IQ and body size, lifestyle and physical fitness associations, a rare case of a dizygotic twin with blood chimerism and definitional issues surrounding amniocentesis-related loss in multiple birth pregnancies. Interesting and informative mention of twins in the media includes twin doctors, a twin freedom fighter, the availability of college scholarships for twins, a new book about the Piccard family (two of whose members were twins), and co-twins born before and after the new year. A follow-up to a previous mention of identical twin biatheletes is also provided.

  7. Multiple rectal carcinoid tumors in monozygotic twins.

    Science.gov (United States)

    Doi, Momoko; Ikawa, Osamu; Taniguchi, Hiroki; Kawamura, Takuji; Katsura, Kanade

    2016-08-01

    We report multiple rectal carcinoid tumors in monozygotic twins who, respectively, had 42 and 36 carcinoid tumors in the lower rectum. This is the first report about carcinoid tumors in monozygotic twins. Both twins developed a similar number of rectal carcinoids with a similar distribution. Investigation of their genetic background may provide information about the origin of these tumors.

  8. Postpartum Mental State of Mothers of Twins

    Science.gov (United States)

    Brantmüller, Éva; Gyúró, Mónika; Galgán, Kitti; Pakai, Annamária

    2016-01-01

    Twin birth is a relevant risk factor for postnatal depression (PND). The primary objective of our study is to reveal the prevalence of suspected cases of depression and to identify some background factors among mothers of twins. We applied convenience sampling method within a retrospective, quantitative study among mothers given birth to twins for…

  9. A RARE CASE OF ACARDIAC TWIN

    OpenAIRE

    Padmaja; Nirmala,

    2015-01-01

    Fetus Acardiacus is a very rare manifestation of twin gestation . This happens due to TRAP sequence . That is Twin reversed arterial perfusion . In this case an amorphous mass was seen on a routine antenatal scan and followed as there was a live twin also . The case report highlights the importance of careful scanning and ...

  10. MIR phasing using merohedrally twinned crystals

    NARCIS (Netherlands)

    Terwisscha van Scheltinga, Anke C.; Valegård, Karin; Hajdu, Janos; Andersson, Inger

    2003-01-01

    Merohedral twinning is a crystal-growth disorder that seriously hinders the determination of macromolecular crystal structures by isomorphous replacement. The strategies used in the structures solved so far are discussed. Several methods can be used to determine the extent of twinning, the twin frac

  11. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  12. [The diagnostic algorithm in twin pregnancy].

    Science.gov (United States)

    Ropacka-Lesiak, Mariola; Szaflik, Krzysztof; Breborowicz, Grzegorz H

    2015-03-01

    This paper presents the diagnostic algorithm in twin pregnancy. The most important sonographic parameters in the assessment of twins have been discussed. Moreover, the most significant complications of twin pregnancy as well as diagnostic possibilities and management, have been also presented and defined.

  13. Natal Influences and Twin Differences: Draft.

    Science.gov (United States)

    Van den Daele, Leland D.

    1972-01-01

    A classification of natal influences is proposed with a model of their operation. Natal influences affect maternal capacity, maternal load, and maternal efficiency. Since maternal load is increased in twin pregnancy, results of twin studies must be generalized with caution. The method of co-twin control is exemplified by examination of a small…

  14. Twin and genetic effects on life events

    NARCIS (Netherlands)

    Middeldorp, C.M.; Cath, D.C.; Vink, J.M.; Boomsma, D.I.

    2005-01-01

    Twin studies that examine the effect of specific environmental risk factors on psychiatric disorders assume that there are no differences in prevalences of these risk factors between twins and singletons. Violation of this assumption signifies that the results from twin studies might not generalize

  15. Concordance for multiple sclerosis in Danish twins

    DEFF Research Database (Denmark)

    Hansen, T; Skytthe, Axel; Stenager, Egon

    2005-01-01

    The occurrence of multiple sclerosis (MS) in twins has not previously been studied in complete nationwide data sets. The existence of almost complete MS and twin registries in Denmark ensures that essentially unbiased samples of MS cases among twins can be obtained. In this population-based study...

  16. The Charles Perkins Centre's Twins Research Node.

    Science.gov (United States)

    Ferreira, Lucas C; Craig, Jeffrey M; Hopper, John L; Carrick, Susan E

    2016-08-01

    Twins can help researchers disentangle the roles of genes from those of the environment on human traits, health, and diseases. To realize this potential, the Australian Twin Registry (ATR), University of Melbourne, and the Charles Perkins Centre (CPC), University of Sydney, established a collaboration to form the Twins Research Node, a highly interconnected research facility dedicated specifically to research involving twins. This collaboration aims to foster the adoption of twin designs as important tools for research in a range of health-related domains. The CPC hosted their Twins Research Node's launch seminar entitled 'Double the power of your research with twin studies', in which experienced twin researchers described how twin studies are supporting scientific discoveries and careers. The launch also featured twin pairs who have actively participated in research through the ATR. Researchers at the CPC were surveyed before the event to gauge their level of understanding and interest in utilizing twin research. This article describes the new Twins Research Node, discusses the survey's main results and reports on the launch seminar.

  17. Glide twinning and pseudotwinning in peristerite: twin morphology and propagation

    Science.gov (United States)

    Brown, William L.

    1989-07-01

    Optically visible Albite glide “twins” in a peristerite (˜An9Or1.6), identified from their tapering shape and relationship to grain boundaries, were studied by transmission electron microscopy. Near the tips in sections ⊥ a, the microstructure consists of small (˜400 nm long) lensshaped Albite twins centred exclusively on the oligoclase lamellae. The lenses extend partly outwards into the two adjacent low albite lamellae and induce strong inhomogeneous strain. Where the lenses are closer together, they form, depending on the sense of shear, nearly linear left or right-stepping en échelon arrays, with overlap of the strain fields. Slightly farther in from the tip, the twin domains coalesce to form continuous pinch-and-swell lamellae, being always thicker in the oligoclase. Because of Si,Al order, only elastic glide pseudotwins are possible in low albite. In oligoclase glide pseudotwins may be mechanically stable (metastable relative to Si,Al order) and may deviate only slightly from true twins. Pseudotwins develop first in the oligoclase, propagate dynamically by jumping across the intervening albite lamellae, extend lengthways and thicken sideways and finally coalesce. They are stabilized by diffusion-controlled inversion of Si,Al order giving rise to true twins described in a companion paper.

  18. NOTE: Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    Science.gov (United States)

    van Gemert, Martin J. C.; Umur, Asli; van den Wijngaard, Jeroen P. H. M.; Van Bavel, Ed; Vandenbussche, Frank P. H. A.; Nikkels, Peter G. J.

    2005-02-01

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival.

  19. Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); VanBavel, Ed [Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Vandenbussche, Frank P H A [Department of Obstetrics, Leiden University Medical Center, Leiden (Netherlands); Nikkels, Peter G J [Department of Pathology, University Medical Center, Utrecht (Netherlands)

    2005-02-07

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival. (note)

  20. The 'Planemo' Twins

    Science.gov (United States)

    2006-08-01

    The cast of exoplanets has an extraordinary new member. Using ESO's telescopes, astronomers have discovered an approximately seven-Jupiter-mass companion to an object that is itself only twice as hefty. Both objects have masses similar to those of extra-solar giant planets, but they are not in orbit around a star - instead they appear to circle each other. The existence of such a double system puts strong constraints on formation theories of free-floating planetary mass objects. ESO PR Photo 29a/06 ESO PR Photo 29a/06 Double System of Planetary Mass Objects (Artist's View) Ray Jayawardhana of the University of Toronto (Canada) and Valentin D. Ivanov of ESO report the discovery in the August 3 issue of Science Express, the rapid online publication service of the journal Science. "This is a truly remarkable pair of twins - each having only about one percent the mass of our Sun," said Jayawardhana. "Its mere existence is a surprise, and its origin and fate a bit of a mystery." Roughly half of all Sun-like stars come in pairs. So do about a sixth of brown dwarfs, 'failed stars' that have less than 75 Jupiter masses and are unable to sustain nuclear fusion in their cores. During the past five years, astronomers have identified a few dozen of even smaller free-floating planetary mass objects, or planemos, in nearby star forming regions. Oph 162225-240515, or Oph1622 for short, is the first planemo found to be a double. The researchers discovered the companion candidate in an optical image taken with ESO's 3.5-m New Technology Telescope at La Silla, Chile. They decided to take optical spectra and infrared images of the pair with ESO's 8.2-m Very Large Telescope to make sure that it is a true companion, instead of a foreground or background star that happens to be in the same line of sight. These follow up observations indeed confirmed that both objects are young, at the same distance, and much too cool to be stars. This suggests the two are physically associated. ESO PR

  1. Ictal EEG modifications in temporal lobe epilepsy.

    Science.gov (United States)

    Pelliccia, Veronica; Mai, Roberto; Francione, Stefano; Gozzo, Francesca; Sartori, Ivana; Nobili, Lino; Lo Russo, Giorgio; Pizzanelli, Chiara; Tassi, Laura

    2013-12-01

    Temporal lobe epilepsy is the most common type of epilepsy in adults with medically intractable, localisation-related epilepsy, amenable to surgery. Together with clinical and neuroimaging data, presurgical ictal scalp-EEG findings are often sufficient to define the epileptogenic zone. It is widely believed that ictal scalp-EEG findings in temporal lobe epilepsy are represented by 5-9-Hz lateralised rhythmic theta activity or 2-5-Hz lateralised rhythmic delta activity. On the basis of experimental models and experience with intra-cerebral EEG recordings, the pattern of low-voltage fast activity is considered to be the electrophysiological hallmark of the epileptogenic zone. We reviewed the ictal scalp-EEG data relating to 111 seizures in 47 patients with temporal lobe epilepsy who underwent video-EEG recordings during presurgical work-up. We found that 35 patients (74.4%) showed flattening, low-voltage fast activity or fast activity as the initial EEG pattern. When visible, the rhythmic delta or theta activity followed the fast activity. Low-voltage fast activity, flattening or fast activity occurs in the majority of patients with temporal lobe epilepsy and represents the main ictal EEG pattern. Low-voltage fast activity (or similar) is also identifiable as the initial ictal EEG pattern in scalp-EEG recordings.

  2. Profiling cytokines in temporal lobe epilepsy

    NARCIS (Netherlands)

    Kan, A.A.

    2012-01-01

    Temporal lobe epilepsy (TLE) is one of the most common types of partial epilepsy. Because about 30% of the TLE patients poorly respond to medication, identification of new drug targets to treat TLE is imperative. This requires detailed knowledge of the pathophysiology of TLE . The aim of this thesis

  3. Centrifugal acceleration in the magnetotail lobes

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2010-02-01

    Full Text Available Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

  4. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    In the past decades, studies on twins have had a great impact on dissecting the genetic and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable samples of twins help to bridge the gap between gene activity and environmental conditions...... through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  5. The Danish political twin study

    DEFF Research Database (Denmark)

    Klemmensen, Robert; Hobolt, Sara B; Dinesen, Peter Thisted

    2012-01-01

    We compare a recent Danish twin survey on political attitudes and behaviors to a nationally representative survey covering similar topics. We find very similar means and variances for most of our constructed scales of political attitudes and behaviors in the two surveys, although even small...

  6. Twin-Arginine Protein Translocation

    NARCIS (Netherlands)

    Goosens, Vivianne J; van Dijl, Jan Maarten

    2016-01-01

    Twin-arginine protein translocation systems (Tat) translocate fully folded and co-factor-containing proteins across biological membranes. In this review, we focus on the Tat pathway of Gram-positive bacteria. The minimal Tat pathway is composed of two components, namely a TatA and TatC pair, which a

  7. Controlling activation site density by low-energy far-field stimulation in cardiac tissue

    Science.gov (United States)

    Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi

    2012-06-01

    Tachycardia and fibrillation are potentially fatal arrhythmias associated with the formation of rotating spiral waves in the heart. Presently, the termination of these types of arrhythmia is achieved by use of antitachycardia pacing or cardioversion. However, these techniques have serious drawbacks, in that they either have limited application or produce undesirable side effects. Low-energy far-field stimulation has recently been proposed as a superior therapy. This proposed therapeutic method would exploit the phenomenon in which the application of low-energy far-field shocks induces a large number of activation sites (“virtual electrodes”) in tissue. It has been found that the formation of such sites can lead to the termination of undesired states in the heart and the restoration of normal beating. In this study we investigate a particular aspect of this method. Here we seek to determine how the activation site density depends on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally, we report numerical results obtained from bidomain simulations of the Beeler-Reuter model that are quantitatively consistent with our experimental results. Also, we derive an intuitive analytical framework that describes the activation site density and provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. The results obtained here should be useful in the development of an actual therapeutic method based on low-energy far-field pacing. In addition, they provide a deeper understanding of the intrinsic properties of cardiac cells.

  8. Twin vaginal delivery: innovate or abdicate.

    Science.gov (United States)

    Easter, Sarah Rae; Taouk, Laura; Schulkin, Jay; Robinson, Julian N

    2017-02-07

    Neonatal safety data along with national guidelines have prompted renewed interest in vaginal delivery of twins, particularly in the case of the noncephalic second twin. Yet, the rising rate of twin cesarean deliveries, coupled with the national decline in operative obstetrics, raises concerns about the availability of providers who are skilled in twin vaginal birth. Providers are key stakeholders for increasing rates of twin vaginal delivery. We surveyed a group of practicing obstetricians to explore potential barriers to the vaginal birth of twins with a focus on delivery of the noncephalic second twin. Among 107 responding providers, only 57% would deliver a noncephalic second twin by breech extraction. Providers who preferred breech extraction had a higher rate of maternal-fetal medicine subspecialty training (26.2% vs 4.3%; P30 sets of twins annually (57.4% vs 34.8%; P=.02). Most providers (54.2%) were familiar with the findings from the recent randomized trial that demonstrated the safety of twin vaginal birth. However, knowledge of the trial was not associated statistically with a preference for breech extraction (62.3% vs 43.5%; P=.05). Providers who preferred breech extraction were more likely to agree with recent society guidelines that encourage the vaginal birth of twins (86.9% vs 63.0%; Pinnovation. Without novel provider-focused strategies, we may relinquish passively the requisite skills for not only our patients but also for future generations of obstetricians.

  9. Fetal growth disorders in twin gestations.

    LENUS (Irish Health Repository)

    Breathnach, Fionnuala M

    2012-06-01

    Twin growth is frequently mismatched. This review serves to explore the pathophysiologic mechanisms that underlie growth aberrations in twin gestations, the prenatal recognition of abnormal twin growth, and the critical importance of stratifying management of abnormal twin growth by chorionicity. Although poor in utero growth of both twins may reflect maternal factors resulting in global uteroplacental dysfunction, discordant twin growth may be attributed to differences in genetic potential between co-twins, placental dysfunction confined to one placenta only, or one placental territory within a shared placenta. In addition, twin-twin transfusion syndrome represents a distinct entity of which discordant growth is a common feature. Discordant growth is recognized as an independent risk factor for adverse perinatal outcome. Intertwin birth weight disparity of 18% or more should be considered to represent a discordance threshold, which serves as an independent risk factor for adverse perinatal outcome. At this cutoff, perinatal morbidity is found to increase both for the larger and the smaller twin within a discordant pair. There remains uncertainty surrounding the sonographic parameters that are most predictive of discordance. Although heightening of fetal surveillance in the face of discordant twin growth follows the principles applied to singleton gestations complicated by fetal growth restriction, the timing of intervention is largely influenced by chorionicity.

  10. Using Twins to Better Understand Sibling Relationships.

    Science.gov (United States)

    Mark, Katharine M; Pike, Alison; Latham, Rachel M; Oliver, Bonamy R

    2017-03-01

    We compared the nature of the sibling relationship in dyads of varying genetic relatedness, employing a behavioural genetic design to estimate the contribution that genes and the environment have on this familial bond. Two samples were used-the Sisters and Brothers Study consisted of 173 families with two target non-twin children (mean ages = 7.42 and 5.22 years respectively); and the Twins, Family and Behaviour study included 234 families with two target twin children (mean age = 4.70 years). Mothers and fathers reported on their children's relationship with each other, via a postal questionnaire (the Sisters and Brothers Study) or a telephone interview (the Twins, Family and Behaviour study). Contrary to expectations, no mean level differences emerged when monozygotic twin pairs, dizygotic twin pairs, and non-twin pairs were compared on their sibling relationship quality. Behavioural genetic analyses also revealed that the sibling bond was modestly to moderately influenced by the genetic propensities of the children within the dyad, and moderately to substantially influenced by the shared environment common to both siblings. In addition, for sibling negativity, we found evidence of twin-specific environmental influence-dizygotic twins showed more reciprocity than did non-twins. Our findings have repercussions for the broader application of results from future twin-based investigations.

  11. Far-Field and Middle-Field Vertical Velocities Associated with Megathrust Earthquakes

    Science.gov (United States)

    Fleitout, L.; Trubienko, O.; Klein, E.; Vigny, C.; Garaud, J.; Shestakov, N.; Satirapod, C.; Simons, W. J.

    2013-12-01

    The recent megathrust earthquakes (Sumatra, Chili and Japan) have induced far-field postseismic subsidence with velocities from a few mm/yr to more than 1cm/yr at distances from 500 to 1500km from the earthquake epicentre, for several years following the earthquake. This subsidence is observed in Argentina, China, Korea, far-East Russia and in Malaysia and Thailand as reported by Satirapod et al. ( ASR, 2013). In the middle-field a very pronounced uplift is localized on the flank of the volcanic arc facing the trench. This is observed both over Honshu, in Chile and on the South-West coast of Sumatra. In Japan, the deformations prior to Tohoku earthquake are well measured by the GSI GPS network: While the East coast was slightly subsiding, the West coast was raising. A 3D finite element code (Zebulon-Zset) is used to understand the deformations through the seismic cycle in the areas surrounding the last three large subduction earthquakes. The meshes designed for each region feature a broad spherical shell portion with a viscoelastic asthenosphere. They are refined close to the subduction zones. Using these finite element models, we find that the pattern of the predicted far-field vertical postseismic displacements depends upon the thicknesses of the elastic plate and of the low viscosity asthenosphere. A low viscosity asthenosphere at shallow depth, just below the lithosphere is required to explain the subsidence at distances from 500 to 1500km. A thick (for example 600km) asthenosphere with a uniform viscosity predicts subsidence too far away from the trench. Slip on the subduction interface is unable tot induce the observed far-field subsidence. However, a combination of relaxation in a low viscosity wedge and slip or relaxation on the bottom part of the subduction interface is necessary to explain the observed postseismic uplift in the middle-field (volcanic arc area). The creep laws of the various zones used to explain the postseismic data can be injected in

  12. A NUMERICAL MODEL OF FAR-FIELD COD CONCENTRATION DISTRIBUTION FOR NATURAL RIVER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A far-field numerical model is developed to simulate jet pollution into natural rivers. Its character is to compute the velocity and pollution concentration separately. The velocity is computed by SIMPLEC algorithm in boundary-fitted coordinate systems. The pollution concentration distribution is computed by developed QUAL-IIm and QAIIL 2D program. The present model was applied to the Xiantao section of the Hanjiang River a tributary of Yangtze River, and Xiangjiang River. The flow field and COD distribution are in good agreement with field data.

  13. Fourier method for recovering acoustic sources from multi-frequency far-field data

    Science.gov (United States)

    Wang, Xianchao; Guo, Yukun; Zhang, Deyue; Liu, Hongyu

    2017-03-01

    We consider an inverse source problem of determining a source term in the Helmholtz equation from multi-frequency far-field measurements. Based on the Fourier series expansion, we develop a novel non-iterative reconstruction method for solving the problem. A promising feature of this method is that it utilizes the data from only a few observation directions for each frequency. Theoretical uniqueness and stability analysis are provided. Numerical experiments are conducted to illustrate the effectiveness and efficiency of the proposed method in both two and three dimensions.

  14. Far-field head-media optical interaction in heat-assisted magnetic recording

    CERN Document Server

    Yang, Ruoxi; Klemmer, Timothy; Olson, Heidi; Zhang, Deming; Perry, Tyler; Yin, Huaqing; Hipwell, Roger; Thiele, Jan-Ulrich; Tang, Huan; Seigler, Mike

    2015-01-01

    We have used a plane-wave expansion method to theoretically study the far-field head-media optical interaction in HAMR. For the ASTC media stack specifically, we notice the outstanding sensitivity related to interlayer's optical thickness for media reflection and magnetic layer's light absorption. With 10-nm interlayer thickness change, the recording layer absorption can be changed by more than 25%. The 2-D results are found to correlate well with full 3-D model and magnetic recording tests on flyable disc with different interlayer thickness.

  15. Self-Similarity in Transverse Intensity Distributions in the Farfield Diffraction Pattern of Radial Walsh Filters

    OpenAIRE

    Mukherjee, P.; L. N. Hazra

    2014-01-01

    In a recent communication we reported the self-similarity in radial Walsh filters. The set of radial Walsh filters have been classified into distinct self-similar groups, where members of each group possess self-similar structures or phase sequences. It has been observed that, the axial intensity distributions in the farfield diffraction pattern of these self-similar radial Walsh filters are also self-similar. In this paper we report the self-similarity in the intensity distributions on a tra...

  16. Phase measurement and far-field reconstruction on externally coupled laser diode arrays.

    Science.gov (United States)

    Niebuhr, Mario; Heuer, Axel

    2017-06-26

    Passive coherent combination of several discrete low power laser diodes is a promising way to overcome the issue of degrading beam quality when scaling single emitters to > 10 W output power. Such systems would be an efficient alternative to current high power sources, yet they suffer from fatal coherence loss when operated well above threshold. We present a new way to obtain detailed coherence information for laser diode arrays using a spatial light modulator to help identify the underlying decoherence processes. Reconstruction tests of the emitted far-field distribution are conducted to evaluate the performance of our setup.

  17. The Optical Chirality Flux as a Useful Far-Field Probe of Chiral Near Fields

    CERN Document Server

    Poulikakos, Lisa V; McPeak, Kevin M; Burger, Sven; Niegemann, Jens; Hafner, Christian; Norris, David J

    2016-01-01

    To optimize the interaction between chiral matter and highly twisted light, quantities that can help characterize chiral electromagnetic fields near nanostructures are needed. Here, by analogy with Poynting's theorem, we formulate the time-averaged conservation law of optical chirality in lossy dispersive media and identify the optical chirality flux as an ideal far-field observable for characterizing chiral optical near fields. Bounded by the conservation law, we show that it provides precise information, unavailable from circular dichroism spectroscopy, on the magnitude and handedness of highly twisted fields near nanostructures.

  18. Near-field to far-field characterization of speckle patterns generated by disordered nanomaterials.

    Science.gov (United States)

    Parigi, Valentina; Perros, Elodie; Binard, Guillaume; Bourdillon, Céline; Maître, Agnès; Carminati, Rémi; Krachmalnicoff, Valentina; De Wilde, Yannick

    2016-04-04

    We study the intensity spatial correlation function of optical speckle patterns above a disordered dielectric medium in the multiple scattering regime. The intensity distributions are recorded by scanning near-field optical microscopy (SNOM) with sub-wavelength spatial resolution at variable distances from the surface in a range which spans continuously from the near-field (distance ≪ λ) to the far-field regime (distance ≫ λ). The non-universal behavior at sub-wavelength distances reveals the connection between the near-field speckle pattern and the internal structure of the medium.

  19. Near-field to far-field characterization of speckle patterns generated by disordered nanomaterials

    CERN Document Server

    Parigi, Valentina; Binard, Guillaume; Bourdillon, Céline; Maître, Agnès; Carminati, Rémi; Krachmalnicoff, Valentina; De Wilde, Yannick

    2016-01-01

    We study the intensity spatial correlation function of optical speckle patterns above a disordered dielectric medium in the multiple scattering regime. The intensity distributions are recorded by scanning near-field optical microscopy (SNOM) with sub-wavelength spatial resolution at variable distances from the surface in a range which spans continuously from the near-field (distance $ \\ll \\lambda $) to the far-field regime (distance $\\gg \\lambda $). The non-universal behavior at sub-wavelength distances reveals the connection between the near-field speckle pattern and the internal structure of the medium.

  20. Reverse design of a bull's eye structure based on the plasmonic far-field pattern.

    Science.gov (United States)

    Yamada, Akira; Terakawa, Mitsuhiro

    2013-09-09

    We present a novel concept on designing a bull's eye structure for a single-wavelength optical source. The plasmonic far-field around a subwavelength aperture on a thin gold film is calculated by finite-difference time-domain method. Based on the annular field intensity distribution on the film surface, we present a method for determining a fairly optimal first groove radius and a periodicity of the grooves that show enhanced transmission. By additionally fine-tuning groove width and groove depth, we have achieved a transmission factor of 9.74. Our novel method has high potential in applications such as silicon infrared sensors.

  1. Tunable far-field acoustic imaging by two-dimensional sonic crystal with concave incident surface

    Science.gov (United States)

    Shen, Feng-Fu; Lu, Dan-Feng; Zhu, Hong-Wei; Ji, Chang-Ying; Shi, Qing-Fan

    2017-01-01

    An additional concave incident surface comprised of two-dimensional (2D) sonic crystals (SCs) is employed to tune the acoustic image in the far-field region. The tunability is realized through changing the curvature of the concave surface. To explain the tuning mechanism, a simple ray-trace analysis is demonstrated based on the wave-beam negative refractive law. Then, a numerical confirmation is carried out. Results show that both the position and the intensity of the image can be tuned by the introduced concave surface.

  2. TRAP Sequence - An Interesting Entity in Twins

    Directory of Open Access Journals (Sweden)

    R H Srinivas Prasad

    2012-01-01

    Full Text Available Twin reversed arterial perfusion (TRAP sequence, is a rare malformation occurring in monozygotic multiple gestations. One well-developed normal (pump twin and the other twin with absent cardiac structure (acardiac, who is hemodynamically dependent on the normal (pump twin are characteristic of this syndrome. The acardiac twin develops multiple anomalies that make survival difficult. The prognosis of the pump twin is variable with mortality rate ranging from 50% to 70%. Complications that affect the prognosis of the pump twin include complications of congestive cardiac failure due to increased cardiac demand, prematurity secondary to preterm delivery, and polyhydramnios. Because of these complications prompt detection, follow-up, and treatment of this condition is very important. We report two cases of TRAP sequence that emphasizes the importance of gray-scale and color Doppler imaging in diagnosis, detection of poor prognostic features, follow-up, and management of TRAP sequence.

  3. Do Twin Boundaries Always Strengthen Metal Nanowires?

    Science.gov (United States)

    Zhang, Yongfeng; Huang, Hanchen

    2009-01-01

    It has been widely reported that twin boundaries strengthen nanowires regardless of their morphology-that is, the strength of nanowires goes up as twin spacing goes down. This article shows that twin boundaries do not always strengthen nanowires. Using classical molecular dynamics simulations, the authors show that whether twin boundaries strengthen nanowires depends on the necessary stress for dislocation nucleation, which in turn depends on surface morphologies. When nanowires are circular cylindrical, the necessary stress of dislocation nucleation is high and the presence of twin boundaries lowers this stress; twin boundaries soften nanowires. In contrast, when nanowires are square cylindrical, the necessary stress of dislocation nucleation is low, and a higher stress is required for dislocations to penetrate twin boundaries; they strengthen nanowires.

  4. Do Twin Boundaries Always Strengthen Metal Nanowires?

    Directory of Open Access Journals (Sweden)

    Zhang Yongfeng

    2008-01-01

    Full Text Available Abstract It has been widely reported that twin boundaries strengthen nanowires regardless of their morphology—that is, the strength of nanowires goes up as twin spacing goes down. This article shows that twin boundaries do not always strengthen nanowires. Using classical molecular dynamics simulations, the authors show that whether twin boundaries strengthen nanowires depends on the necessary stress for dislocation nucleation, which in turn depends on surface morphologies. When nanowires are circular cylindrical, the necessary stress of dislocation nucleation is high and the presence of twin boundaries lowers this stress; twin boundaries soften nanowires. In contrast, when nanowires are square cylindrical, the necessary stress of dislocation nucleation is low, and a higher stress is required for dislocations to penetrate twin boundaries; they strengthen nanowires.

  5. Aura in temporal lobe epilepsy: clinical and electroencephalographic correlation.

    OpenAIRE

    1983-01-01

    Patients with temporal lobe epilepsy were evaluated for their aura and the site of EEG abnormality. Autonomic and psychic auras were more frequently associated with right-sided temporal lobe lesions in 290 patients.

  6. Analysis of complications in hepatic right lobe living donors

    OpenAIRE

    Azzam, Ayman; Uryuhara, Kinji; Taka, Ito; Takada, Yasutsugu; Egawa, Hiroto; TANAKA, Koichi

    2010-01-01

    BACKGROUND AND OBJECTIVES: Living donor liver transplantation (LDLT) has been expanding to adult recipients by using right lobe grafts. However, the incidence of complications is more frequent than that involving left lobe grafts. Hence, we aimed to analyze postoperative complications in right lobe liver donors as a step to improve the results in the donors. METHODS: Three hundred and eleven right lobe liver donors were retrospectively reviewed between February 1998 and December 2003. RESULTS...

  7. Parietal lobe epilepsy: the great imitator among focal epilepsies.

    Science.gov (United States)

    Ristić, Aleksandar J; Alexopoulos, Andreas V; So, Norman; Wong, Chong; Najm, Imad M

    2012-03-01

    Comprising large areas of association cortex, the parietal lobe is part of an extensive synaptic network elaborately intertwined with other brain regions. We hypothesize that such widespread projections are responsible for producing inaccurate localisation readings on scalp EEG and clinical semiology in patients with parietal lobe epilepsies, as opposed to frontal or temporal lobe epilepsies. Our study included 50 patients with pharmacoresistant focal epilepsy, who were subsequently rendered seizure-free for ≥12 months (median: 23 months) following resections limited to the frontal (n=17), temporal (n=17), or parietal (n=16) lobes. Interictal and ictal EEG data with accompanying seizure video recordings were extracted from archived files of scalp video-EEG monitoring. Two blinded raters independently reviewed the EEG according to predetermined criteria. Videos of seizures were then observed, as raters formulated their final electroclinical impression (ECI), identifying patients' abnormal neuronal activities with parietal, temporal, and frontal lobe epilepsy, or unspecified localisation. Groups did not differ significantly in demographics, age at epilepsy onset, or presence of MRI abnormalities. Interictal discharges in parietal lobe epilepsy showed the greatest magnitude of scatter outside the lobe of origin; the majority of patients with parietal lobe epilepsy had more than one spike population (pparietal lobe epilepsy cases (p=0.024). Whenever raters confidently limited their ECI to one lobar subtype, overall accuracy was excellent. Lobar classifications by ECI were highly accurate for temporal lobe epilepsy, vacillating in frontal lobe epilepsy, and least accurate in parietal lobe epilepsy subjects. Scalp EEG readings of parietal lobe epilepsy patients showed a more variable scatter of interictal discharges and a lower localisation value of ictal recordings compared to temporal and frontal lobe epilepsy subjects, suggesting an increased likelihood of

  8. The extratemporal lobe epilepsies in the epilepsy monitoring unit

    Science.gov (United States)

    Dash, Deepa; Tripathi, Manjari

    2014-01-01

    Extratemporal lobe epilepsies (ETLE) are characterized by the epileptogenic foci outside the temporal lobe. They have a wide spectrum of semiological presentation depending upon the site of origin. They can arise from frontal, parietal, occipital lobes and from hypothalamic hamartoma. We discuss in this review the semiology of different types of ETLE encountered in the epilepsy monitoring unit. PMID:24791090

  9. Metal/Polymer Based Stretchable Antenna for Constant Frequency Far-Field Communication in Wearable Electronics

    KAUST Repository

    Hussain, Aftab M.

    2015-10-06

    Body integrated wearable electronics can be used for advanced health monitoring, security, and wellness. Due to the complex, asymmetric surface of human body and atypical motion such as stretching in elbow, finger joints, wrist, knee, ankle, etc. electronics integrated to body need to be physically flexible, conforming, and stretchable. In that context, state-of-the-art electronics are unusable due to their bulky, rigid, and brittle framework. Therefore, it is critical to develop stretchable electronics which can physically stretch to absorb the strain associated with body movements. While research in stretchable electronics has started to gain momentum, a stretchable antenna which can perform far-field communications and can operate at constant frequency, such that physical shape modulation will not compromise its functionality, is yet to be realized. Here, a stretchable antenna is shown, using a low-cost metal (copper) on flexible polymeric platform, which functions at constant frequency of 2.45 GHz, for far-field applications. While mounted on a stretchable fabric worn by a human subject, the fabricated antenna communicated at a distance of 80 m with 1.25 mW transmitted power. This work shows an integration strategy from compact antenna design to its practical experimentation for enhanced data communication capability in future generation wearable electronics.

  10. Far-field radially polarized focal spot from plasmonic spiral structure combined with central aperture antenna

    Science.gov (United States)

    Mao, Lei; Ren, Yuan; Lu, Yonghua; Lei, Xinrui; Jiang, Kang; Li, Kuanguo; Wang, Yong; Cui, Chenjing; Wen, Xiaolei; Wang, Pei

    2016-03-01

    Manipulation of a vector micro-beam with an optical antenna has significant potentials for nano-optical technology applications including bio-optics, optical fabrication, and quantum information processing. We have designed and demonstrated a central aperture antenna within an Archimedean spiral that extracts the bonding plasmonic field from a surface to produce a new vector focal spot in far-field. The properties of this vector focal field are revealed by confocal microscopy and theoretical simulations. The pattern, polarization and phase of the focal field are determined by the incident light and by the chirality of the Archimedean spiral. For incident light with right-handed circular polarization, the left-handed spiral (one-order chirality) outputs a micro-radially polarized focal field. Our results reveal the relationship between the near-field and far-field distributions of the plasmonic spiral structure, and the structure has the potential to lead to advances in diverse applications such as plasmonic lenses, near-field angular momentum detection, and optical tweezers.

  11. Far-field nanoscale infrared spectroscopy of vibrational fingerprints of molecules with graphene plasmons

    Science.gov (United States)

    Hu, Hai; Yang, Xiaoxia; Zhai, Feng; Hu, Debo; Liu, Ruina; Liu, Kaihui; Sun, Zhipei; Dai, Qing

    2016-01-01

    Infrared spectroscopy, especially for molecular vibrations in the fingerprint region between 600 and 1,500 cm−1, is a powerful characterization method for bulk materials. However, molecular fingerprinting at the nanoscale level still remains a significant challenge, due to weak light–matter interaction between micron-wavelengthed infrared light and nano-sized molecules. Here we demonstrate molecular fingerprinting at the nanoscale level using our specially designed graphene plasmonic structure on CaF2 nanofilm. This structure not only avoids the plasmon–phonon hybridization, but also provides in situ electrically-tunable graphene plasmon covering the entire molecular fingerprint region, which was previously unattainable. In addition, undisturbed and highly confined graphene plasmon offers simultaneous detection of in-plane and out-of-plane vibrational modes with ultrahigh detection sensitivity down to the sub-monolayer level, significantly pushing the current detection limit of far-field mid-infrared spectroscopies. Our results provide a platform, fulfilling the long-awaited expectation of high sensitivity and selectivity far-field fingerprint detection of nano-scale molecules for numerous applications. PMID:27460765

  12. Far-field nanoscale infrared spectroscopy of vibrational fingerprints of molecules with graphene plasmons

    Science.gov (United States)

    Hu, Hai; Yang, Xiaoxia; Zhai, Feng; Hu, Debo; Liu, Ruina; Liu, Kaihui; Sun, Zhipei; Dai, Qing

    2016-07-01

    Infrared spectroscopy, especially for molecular vibrations in the fingerprint region between 600 and 1,500 cm-1, is a powerful characterization method for bulk materials. However, molecular fingerprinting at the nanoscale level still remains a significant challenge, due to weak light-matter interaction between micron-wavelengthed infrared light and nano-sized molecules. Here we demonstrate molecular fingerprinting at the nanoscale level using our specially designed graphene plasmonic structure on CaF2 nanofilm. This structure not only avoids the plasmon-phonon hybridization, but also provides in situ electrically-tunable graphene plasmon covering the entire molecular fingerprint region, which was previously unattainable. In addition, undisturbed and highly confined graphene plasmon offers simultaneous detection of in-plane and out-of-plane vibrational modes with ultrahigh detection sensitivity down to the sub-monolayer level, significantly pushing the current detection limit of far-field mid-infrared spectroscopies. Our results provide a platform, fulfilling the long-awaited expectation of high sensitivity and selectivity far-field fingerprint detection of nano-scale molecules for numerous applications.

  13. Far-field radially polarized focal spot from plasmonic spiral structure combined with central aperture antenna

    Science.gov (United States)

    Mao, Lei; Ren, Yuan; Lu, Yonghua; Lei, Xinrui; Jiang, Kang; Li, Kuanguo; Wang, Yong; Cui, Chenjing; Wen, Xiaolei; Wang, Pei

    2016-01-01

    Manipulation of a vector micro-beam with an optical antenna has significant potentials for nano-optical technology applications including bio-optics, optical fabrication, and quantum information processing. We have designed and demonstrated a central aperture antenna within an Archimedean spiral that extracts the bonding plasmonic field from a surface to produce a new vector focal spot in far-field. The properties of this vector focal field are revealed by confocal microscopy and theoretical simulations. The pattern, polarization and phase of the focal field are determined by the incident light and by the chirality of the Archimedean spiral. For incident light with right-handed circular polarization, the left-handed spiral (one-order chirality) outputs a micro-radially polarized focal field. Our results reveal the relationship between the near-field and far-field distributions of the plasmonic spiral structure, and the structure has the potential to lead to advances in diverse applications such as plasmonic lenses, near-field angular momentum detection, and optical tweezers. PMID:27009383

  14. High order local absorbing boundary conditions for acoustic waves in terms of farfield expansions

    Science.gov (United States)

    Villamizar, Vianey; Acosta, Sebastian; Dastrup, Blake

    2017-03-01

    We devise a new high order local absorbing boundary condition (ABC) for radiating problems and scattering of time-harmonic acoustic waves from obstacles of arbitrary shape. By introducing an artificial boundary S enclosing the scatterer, the original unbounded domain Ω is decomposed into a bounded computational domain Ω- and an exterior unbounded domain Ω+. Then, we define interface conditions at the artificial boundary S, from truncated versions of the well-known Wilcox and Karp farfield expansion representations of the exact solution in the exterior region Ω+. As a result, we obtain a new local absorbing boundary condition (ABC) for a bounded problem on Ω-, which effectively accounts for the outgoing behavior of the scattered field. Contrary to the low order absorbing conditions previously defined, the error at the artificial boundary induced by this novel ABC can be easily reduced to reach any accuracy within the limits of the computational resources. We accomplish this by simply adding as many terms as needed to the truncated farfield expansions of Wilcox or Karp. The convergence of these expansions guarantees that the order of approximation of the new ABC can be increased arbitrarily without having to enlarge the radius of the artificial boundary. We include numerical results in two and three dimensions which demonstrate the improved accuracy and simplicity of this new formulation when compared to other absorbing boundary conditions.

  15. Executive Functioning and Dysfunctional Schema Modes in Individuals with Frontal Lobe Lesion and Temporal Lobe Epilepsy; Mega Case Analysis

    Directory of Open Access Journals (Sweden)

    Sabir Zaman

    2016-01-01

    Full Text Available The present study was to investigate the executive functioning like selective attention, cognitive flexibility, processing speed and executive processing abilities in individuals with frontal lobe lesion and temporal lobe epilepsy by using a tool Stroop Neuropsychological Screening Test [1]. The study also tried to explore emotional problems, cognitive state, specific behavioral responses and coping strategies of individuals with frontal lobe lesion and temporal lobe epilepsy. The present study was also designed to develop the reflective understanding of dysfunctional and healthy modes of individuals of frontal lobe lesion and temporal lobe epilepsy measure through Schema Mode Inventory Urdu version [2]. The sample of the present study consisted of 08 cases 04 cases related to frontal lobe lesion and 04 cases of temporal lobe epilepsy. Our finding indicated that the individuals of frontal lobe lesion and temporal lobe epilepsy were found significantly engaged in dysfunctional modes, such as Child Modes, Maladaptive and Punitive Parents Modes. On Stroop Test the Standard Deviation of individuals with frontal lobe lesion (74.18 and temporal lobe epilepsy (59.25 both the values are below the standard value (98 which shows the significant level. The Stroop Test measure executive functioning like selective attention executive processing, cognitive flexibility and inhibition control all these qualities are low and poor in individuals with frontal lobe lesion and temporal lobe epilepsy. The individuals with frontal lobe lesion and temporal lobe epilepsy were engaged in dysfunctional modes such as Child Modes, Maladaptive and Punitive Parent Modes are positively associated with executive functioning. Individuals with dysfunctional schema modes are lower score on Stroop test.

  16. Executive Functioning and Dysfunctional Schema Modes in Individuals with Frontal Lobe Lesion and Temporal Lobe Epilepsy; Mega Case Analysis

    OpenAIRE

    Sabir Zaman

    2016-01-01

    The present study was to investigate the executive functioning like selective attention, cognitive flexibility, processing speed and executive processing abilities in individuals with frontal lobe lesion and temporal lobe epilepsy by using a tool Stroop Neuropsychological Screening Test [1]. The study also tried to explore emotional problems, cognitive state, specific behavioral responses and coping strategies of individuals with frontal lobe lesion and temporal lobe epilepsy. The present stu...

  17. Galaxies with Supermassive Binary Black Holes: (III) The Roche Lobes and Jiang-Yeh Lobe in a Core System

    CERN Document Server

    Yeh, Li-Chin

    2016-01-01

    Three-dimensional equi-potential surfaces of a galactic system with supermassive binary black holes are discussed herein. The conditions of topological transitions for the important surfaces, i.e. Roche Lobes and Jiang-Yeh Lobe, are studied in this paper. In addition, the mathematical properties of the Jacobi surfaces are investigated analytically. Finally, a numerical procedure for determining the regions of the Roche Lobes and Jiang-Yeh Lobe is suggested.

  18. Is the Posterior Parietal Lobe Involved in Working Memory Retrieval? Evidence from Patients with Bilateral Parietal Lobe Damage

    OpenAIRE

    Marian E Berryhill; Olson, Ingrid R.

    2008-01-01

    Neuroimaging evidence suggests that the parietal lobe has an important role in memory retrieval, yet neuropsychology is largely silent on this topic. Recently, we reported that unilateral parietal lobe damage impairs various forms of visual working memory when tested by old/new recognition. Here, we investigate whether parietal lobe working memory deficits are linked to problems at retrieval. We tested two patients with bilateral parietal lobe damage in a series of visual working memory tasks...

  19. Is the posterior parietal lobe involved in working memory retrieval? Evidence from patients with bilateral parietal lobe damage

    OpenAIRE

    Berryhill, M.E; Olson, I.R.

    2008-01-01

    Neuroimaging evidence suggests that the parietal lobe has an important role in memory retrieval, yet neuropsychology is largely silent on this topic. Recently, we reported that unilateral parietal lobe damage impairs various forms of visual working memory when tested by old/new recognition. Here, we investigate whether parietal lobe working memory deficits are linked to problems at retrieval. We tested two patients with bilateral parietal lobe damage in a series of visual working memory tasks...

  20. Fingerprint recognition with identical twin fingerprints.

    Directory of Open Access Journals (Sweden)

    Xunqiang Tao

    Full Text Available Fingerprint recognition with identical twins is a challenging task due to the closest genetics-based relationship existing in the identical twins. Several pioneers have analyzed the similarity between twins' fingerprints. In this work we continue to investigate the topic of the similarity of identical twin fingerprints. Our study was tested based on a large identical twin fingerprint database that contains 83 twin pairs, 4 fingers per individual and six impressions per finger: 3984 (83*2*4*6 images. Compared to the previous work, our contributions are summarized as follows: (1 Two state-of-the-art fingerprint identification methods: P071 and VeriFinger 6.1 were used, rather than one fingerprint identification method in previous studies. (2 Six impressions per finger were captured, rather than just one impression, which makes the genuine distribution of matching scores more realistic. (3 A larger sample (83 pairs was collected. (4 A novel statistical analysis, which aims at showing the probability distribution of the fingerprint types for the corresponding fingers of identical twins which have same fingerprint type, has been conducted. (5 A novel analysis, which aims at showing which finger from identical twins has higher probability of having same fingerprint type, has been conducted. Our results showed that: (a A state-of-the-art automatic fingerprint verification system can distinguish identical twins without drastic degradation in performance. (b The chance that the fingerprints have the same type from identical twins is 0.7440, comparing to 0.3215 from non-identical twins. (c For the corresponding fingers of identical twins which have same fingerprint type, the probability distribution of five major fingerprint types is similar to the probability distribution for all the fingers' fingerprint type. (d For each of four fingers of identical twins, the probability of having same fingerprint type is similar.

  1. The relationship between twin language, twins' close ties, and social competence.

    Science.gov (United States)

    Hayashi, Chisato; Mikami, Hiroshi; Nishihara, Reiko; Maeda, Chiho; Hayakawa, Kazuo

    2014-02-01

    This study investigated the relationship between twin language, twins' close ties, and social competence in a prospective longitudinal study. We hypothesized that twins whose tie is close would be more likely to develop a twin language, and these twins would be less likely to develop social competence. In addition, we hypothesize that some environmental factors, such as having an older sibling, preschool attendance, zygosity, and sex are also related to twin language, twins' close ties, and social competence. At baseline in 1999 a mailed questionnaire survey was conducted, and a follow-up questionnaire was distributed in 2004 among 958 mothers. As a result, 516 respondents returned the questionnaire (53.9%). In this study, we used 261 twin pairs aged from 6 to 12 years (school-age children) for analysis, excluding those with missing values. In the present study, we found that zygosity and sex were associated with twins' close ties. Having an older sibling and preschool attendance did not affect the twins' close tie, twin language, or social competence. One of the most important findings was that social competence was not affected directly by twins' close tie, but was affected when a twin language was found.

  2. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  3. Criminal Responsibility of the Frontal Lobe Syndrome.

    Science.gov (United States)

    Sener, Mustafa Talip; Ozcan, Halil; Sahingoz, Sadik; Ogul, Hayri

    2015-10-01

    Neurological and/or psychiatric symptoms might be detected due to damage of frontal lobes as detected in damages of many brain regions. Frontal lobe syndrome (FLS) occurs as a result of damage in prefrontal region due to various causes. Symptoms due to prefrontal region damage, varies according to the size and location of the lesion. In most of the cases; executive dysfunctions, attention deficits, inconsistencies in social life, impulse control problems, obsessive behaviors and violence behaviors are common clinical signs. Behavioral symptoms seen in FLS can be confused with personality disorders and negative symptoms of schizophrenia. FLS is a neuropsychiatric disorder rarely assessed in forensic psychiatry and in terms of detection of criminal responsibility. In this case report, criminal responsibility in FLS was assessed through a FLS case in which an offense of "threat" was committed and investigated in terms of criminal responsibility.

  4. Cephalic aura after frontal lobe resection.

    Science.gov (United States)

    Kakisaka, Yosuke; Jehi, Lara; Alkawadri, Rafeed; Wang, Zhong I; Enatsu, Rei; Mosher, John C; Dubarry, Anne-Sophie; Alexopoulos, Andreas V; Burgess, Richard C

    2014-08-01

    A cephalic aura is a common sensory aura typically seen in frontal lobe epilepsy. The generation mechanism of cephalic aura is not fully understood. It is hypothesized that to generate a cephalic aura extensive cortical areas need to be excited. We report a patient who started to have cephalic aura after right frontal lobe resection. Magnetoencephalography (MEG) showed interictal spike and ictal change during cephalic aura, both of which were distributed in the right frontal region, and the latter involved much more widespread areas than the former on MEG sensors. The peculiar seizure onset pattern may indicate that surgical modification of the epileptic network was related to the appearance of cephalic aura. We hypothesize that generation of cephalic aura may be associated with more extensive cortical involvement of epileptic activity than that of interictal activity, in at least a subset of cases.

  5. The Spread of Substance Use and Delinquency between Adolescent Twins

    Science.gov (United States)

    Laursen, Brett; Hartl, Amy C.; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Boivin, Michel

    2017-01-01

    This investigation examines the spread of problem behaviors (substance use and delinquency) between twin siblings. A sample of 628 twins (151 male twin pairs and 163 female twin pairs) drawn from the Quebec Newborn Twin Study completed inventories describing delinquency and substance use at ages 13, 14, and 15. A 3-wave longitudinal actor-partner…

  6. Perirhinal cortex and temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Giuseppe eBiagini

    2013-08-01

    Full Text Available The perirhinal cortex – which is interconnected with several limbic structures and is intimately involved in learning and memory - plays major roles in pathological processes such as the kindling phenomenon of epileptogenesis and the spread of limbic seizures. Both features may be relevant to the pathophysiology of mesial temporal lobe epilepsy that represents the most refractory adult form of epilepsy with up to 30% of patients not achieving adequate seizure control. Compared to other limbic structures such as the hippocampus or the entorhinal cortex, the perirhinal area remains understudied and, in particular, detailed information on its dysfunctional characteristics remains scarce; this lack of information may be due to the fact that the perirhinal cortex is not grossly damaged in mesial temporal lobe epilepsy and in models mimicking this epileptic disorder. However, we have recently identified in pilocarpine-treated epileptic rats the presence of selective losses of interneuron subtypes along with increased synaptic excitability. In this review we: (i highlight the fundamental electrophysiological properties of perirhinal cortex neurons; (ii briefly stress the mechanisms underlying epileptiform synchronization in perirhinal cortex networks following epileptogenic pharmacological manipulations; and (iii focus on the changes in neuronal excitability and cytoarchitecture of the perirhinal cortex occurring in the pilocarpine model of mesial temporal lobe epilepsy. Overall, these data indicate that perirhinal cortex networks are hyperexcitable in an animal model of temporal lobe epilepsy, and that this condition is associated with a selective cellular damage that is characterized by an age-dependent sensitivity of interneurons to precipitating injuries, such as status epilepticus.

  7. Dimorphic olfactory lobes in the arthropoda.

    Science.gov (United States)

    Strausfeld, Nicholas; Reisenman, Carolina E

    2009-07-01

    Specialized olfactory lobe glomeruli relating to sexual or caste differences have been observed in at least five orders of insects, suggesting an early appearance of this trait in insect evolution. Dimorphism is not limited to nocturnal species, but occurs even in insects that are known to use vision for courtship. Other than a single description, there is no evidence for similar structures occurring in the Crustacea, suggesting that the evolution of dimorphic olfactory systems may typify terrestrial arthropods.

  8. Einstein's Clocks and Langevin's Twins

    CERN Document Server

    Weinstein, Galina

    2012-01-01

    In 1905 Einstein presented the Clock Paradox and in 1911 Paul Langevin expanded Einstein's result to human observers, the "Twin Paradox." I will explain the crucial difference between Einstein and Langevin. Einstein did not present the so-called "Twin Paradox." Later Einstein continued to speak about the clock paradox. Einstein might not have been interested in the question: what happens to the observers themselves. The reason for this could be the following; Einstein dealt with measurement procedures, clocks and measuring rods. Einstein's observers were measuring time with these clocks and measuring rods. Einstein might not have been interested in so-called biology of the observers, whether these observers were getting older, younger, or whether they have gone any other changes; these changes appeared to be out of the scope of his "Principle of relativity" or kinematics. The processes and changes occurring within observers seemed to be good for philosophical discussions. Later writers criticized Einstein's c...

  9. Occipital lobe infarction and positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tagawa, Koichi; Nagata, Ken; Shishido, Fumio (Research Inst. of Brain and Blood Vessels, Akita (Japan))

    1990-08-01

    Even though the PET study revealed a total infarct in the territory of the left PCA in our 3 cases of pure alesia, it is still obscure which part of the left occipital lobe is most closely associated with the occurrence of the pure alexia. In order to elucidate the intralobar localization of the pure alexia, it is needed to have an ideal case who shows an pure alexia due to the localized lesion within the left occipital lobe. Furthermore, high-resolution PET scanner will circumvent the problem in detecting the metabolism and blood flow in the corpus callosum which plays an important role in the pathogenesis. We have shown that the occlusion of the right PCA also produced a left unilateral agnosia which is one of the common neurological signs in the right MCA infarction. To tell whether the responsible lesion for the unilateral spatial agnosia differs between the PCA occlusion and the MCA occlusion, the correlation study should be carried out in a greater number of the subjects. Two distinctive neuropsychological manifestations, cerebral color blidness and prosopagnosia, have been considered to be produced by the bilateral occipital lesion. The PET studies disclosed reduction of blood flow and oxygen metabolism in both occipital lobes in our particular patient who exibited cerebral color blindness and posopagnosia. (author).

  10. Human frontal lobes are not relatively large.

    Science.gov (United States)

    Barton, Robert A; Venditti, Chris

    2013-05-28

    One of the most pervasive assumptions about human brain evolution is that it involved relative enlargement of the frontal lobes. We show that this assumption is without foundation. Analysis of five independent data sets using correctly scaled measures and phylogenetic methods reveals that the size of human frontal lobes, and of specific frontal regions, is as expected relative to the size of other brain structures. Recent claims for relative enlargement of human frontal white matter volume, and for relative enlargement shared by all great apes, seem to be mistaken. Furthermore, using a recently developed method for detecting shifts in evolutionary rates, we find that the rate of change in relative frontal cortex volume along the phylogenetic branch leading to humans was unremarkable and that other branches showed significantly faster rates of change. Although absolute and proportional frontal region size increased rapidly in humans, this change was tightly correlated with corresponding size increases in other areas and whole brain size, and with decreases in frontal neuron densities. The search for the neural basis of human cognitive uniqueness should therefore focus less on the frontal lobes in isolation and more on distributed neural networks.

  11. Identical twins in forensic genetics

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Morling, Niels

    2015-01-01

    The increase in the number of forensic genetic loci used for identification purposes results in infinitesimal random match probabilities. These probabilities are computed under assumptions made for rather simple population genetic models. Often, the forensic expert reports likelihood ratios, where...... published results accounting for close familial relationships. However, we revisit the discussion to increase the awareness among forensic genetic practitioners and include new information on medical and societal factors to assess the risk of not considering a monozygotic twin as the true perpetrator...

  12. Geographic Tongue in Monozygotic Twins

    OpenAIRE

    Shekhar M, Guna

    2014-01-01

    This article discusses a case of 5-year-old girl monozygotic twins who were suffering from geographic tongue (GT), a benign inflammatory disorder of the tongue which is characterized by circinate, irregular erythematous lesions on the dorsum and lateral borders of the tongue caused by loss of filiform papillae of the tongue epithelium. Whilst geographic tongue is a common entity, reports on this condition are uncommon in the literature. To best of our knowledge, this is the first report which...

  13. Conjoined omphalopagus twins: a casereport

    Directory of Open Access Journals (Sweden)

    Sheila Yadira Gómez-Murillo

    2014-11-01

    Full Text Available Multiple pregnancies are 3% of the total. The most frequent are dizygotic females, however, a small group of them are of monozygotic conjoined twins in some anatomical area. This attracts the attention of physicians because of the rarity of the condition and the difficulties as well as the ethical dilemmas for their treatment. We report a case of male Siamese omphalopagus. They were separated surgically at seven weeks of age. One of them lived six months.

  14. Thrombosis of anastomoses may affect the staging sequence of twin-twin transfusion syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Wijngaard, Jeroen P H M van den; Gemert, Martin J C van [Laser Center, Academic Medical Center-University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Ross, Michael G [Department of Obstetrics and Gynecology, Harbor-UCLA School of Medicine, Torrance, CA 90502 (United States)], E-mail: j.p.vandenwijngaard@amc.uva.nl

    2008-03-07

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. (note)

  15. Twins eye study in Tasmania (TEST): rationale and methodology to recruit and examine twins.

    Science.gov (United States)

    Mackey, David A; Mackinnon, Jane R; Brown, Shayne A; Kearns, Lisa S; Ruddle, Jonathan B; Sanfilippo, Paul G; Sun, Cong; Hammond, Christopher J; Young, Terri L; Martin, Nicholas G; Hewitt, Alex W

    2009-10-01

    Visual impairment is a leading cause of morbidity and poor quality of life in our community. Unravelling the mechanisms underpinning important blinding diseases could allow preventative or curative steps to be implemented. Twin siblings provide a unique opportunity in biology to discover genes associated with numerous eye diseases and ocular biometry. Twins are particularly useful for quantitative trait analysis through genome-wide association and linkage studies. Although many studies involving twins rely on twin registries, we present our approach to the Twins Eye Study in Tasmania to provide insight into possible recruitment strategies, expected participation rates and potential examination strategies that can be considered by other researchers for similar studies. Five separate avenues for cohort recruitment were adopted: (1) piggy-backing existing studies where twins had been recruited, (2) utilizing the national twin registry, (3) word-of-mouth and local media publicity, (4) directly approaching schools, and finally (5) collaborating with other research groups studying twins.

  16. The TWINS Science Data System after the launch of TWINS 1

    Science.gov (United States)

    Goldstein, J.; Valek, P.; Skoug, R.; Delapp, D.; Redfern, J.; Carruth, B.; McComas, D.

    2007-05-01

    The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) 1 satellite is in orbit and science data are expected to commence in the near future. TWINS-1 comprises half of the TWINS stereoscopic neutral atom imaging system that will advance our knowledge of the Earth's ring current. To support the expected data return, we have developed a Science Data System (SDS) for the TWINS mission. The TWINS SDS is an IDL- and Java- driven data interface that operates primarily via a web browser, and has as its spine an SQL-queryable database. Through this interface, TWINS science data will be provided to the TWINS team, the space science community, and the public. In this paper we present the current and future capabilities of the TWINS SDS, as well as how the SDS fits into virtual observatory infrastructure.

  17. Register-based research on twins

    DEFF Research Database (Denmark)

    Christensen, Kaare; Ohm Kyvik, Kirsten; Holm, Niels V

    2011-01-01

    Introduction: The Danish Twin Registry (DTR) has for more than 50 years been based on surveys and clinical investigations and over the two last decades also on register linkage. Currently these two approaches are merged within Statistics Denmark. Research topics: Here we report on three major...... groups of register-based research in the DTR that used the uniqueness of twinning. First, we focus on the ''long-term prognosis'' of being a twin compared with being a singleton and show that Danish twins have health trajectories in adulthood similar to singletons, which is a result of interest for twins...... and their families as well as a test of the fetal origins hypothesis that states that fetal growth restriction has long-term health consequences. Secondly, we summarise some of the most important register-based ''classical twin studies'', e.g. heritability studies on lifespan and exceptional longevity. Finally, we...

  18. Twin delivery: method, timing and conduct.

    Science.gov (United States)

    Barrett, Jon F R

    2014-02-01

    The incidence of twin pregnancy has increased worldwide over the past 10 years, largely as a consequence of the assisted reproductive technologies. Issues such as intrapartum monitoring and operative interventions, especially relating to the second twin, provide a unique challenge in labour and delivery. Epidemiological and cohort data suggest that twins have a three-fold higher mortality rate than singletons, and that the second twin might have a better outcome if delivered by lower segment caesarean section. The recently completed Twin Birth Study has found that planned vaginal lower segment caesarean section is not advantageous to the fetus. In the light of this large randomised-controlled trial, vaginal delivery if twin A presents by the vertex is recommended as long as guidelines for the conduct of such delivery are followed.

  19. A Twin Study of Perthes Disease

    DEFF Research Database (Denmark)

    Metcalfe, David; Van Dijck, Stephanie; Parsons, Nicolas

    2016-01-01

    and genetic associations with LCPD. METHODS: We extracted all twin pairs from the Danish Twin Registry (DTR) in which at least 1 individual had LCPD. The DTR captures every twin pair born alive in Denmark, and those with LCPD were identified by using health record linkage. Probanwise concordance.......00-0.18) for the dizygotic, and 0.18 (95% CI: 0.00-0.40) for the UZ twin pairs. CONCLUSIONS: This study found evidence of familial clustering in LCPD but did not show a genetic component. The absolute risk that a co-twin of an affected individual will develop LCPD is low, even in the case of monozygotic twin pairs.......BACKGROUND: Legg-Calvé-Perthes disease (LCPD) is an idiopathic avascular necrosis of the femoral head. Its etiology is poorly understood, although previous studies have implicated low birth weight and possible genetic determinants. The aim of this study was to identify potential birth weight...

  20. (120) and (122-bar) monazite deformation twins

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R.S

    2003-10-20

    Unusual features of (120) and (122-bar) deformation twins in monazite (monoclinic LaPO{sub 4}) are described and analyzed. These features are kinks and other irregularities in (120) twins, and V-shaped indentations on (120) and (122-bar) twin planes. Twinning shear analysis suggests that the kinks are a type II deformation twin mode with shear direction ({eta}{sub 1}) of [21-bar0]. This complements previous analysis based on atom shuffling considerations. Shear strain compatibility requires extensive plastic deformation in the kink. The V-shaped indentations may be analogous to similar structures in b.c.c metal deformation twins. Deformation mechanisms that may be associated with these structures are discussed.

  1. Fullerton Virtual Twin Study: an update.

    Science.gov (United States)

    Segal, Nancy L; McGuire, Shirley A; Graham, Jamie L; Stohs, Joanne Hoven

    2013-02-01

    Virtual twins (VTs) are same-age unrelated siblings reared together from early infancy. These unique sibling sets replicate twinship, but without the genetic link. The first VT pair was identified and studied at the University of Minnesota in 1990, launching the development of the Fullerton Virtual Twin Study at California State University, Fullerton (CSUF) in 1991. The registry currently includes 151 pairs, mostly children, with new pairs identified on a continuous basis. Research with VTs includes studies of general intelligence, body size, interpersonal trust, social coordination, social networks, and parenting. In some cases, VTs have been studied in conjunction with pairs of monozygotic twins, dizygotic twins, full siblings, and friends as part of TAPS (Twins, Adoptees, Peers and Siblings), a collaborative project conducted between CSUF and the University of San Francisco, 2002-2006. VTs will also serve as a comparison group for epigenetic analyses of young Chinese twins reared apart and together.

  2. Twinning of Polymer Crystals Suppressed by Entropy

    Directory of Open Access Journals (Sweden)

    Nikos Ch. Karayiannis

    2014-09-01

    Full Text Available We propose an entropic argument as partial explanation of the observed scarcity of twinned structures in crystalline samples of synthetic organic polymeric materials. Polymeric molecules possess a much larger number of conformational degrees of freedom than low molecular weight substances. The preferred conformations of polymer chains in the bulk of a single crystal are often incompatible with the conformations imposed by the symmetry of a growth twin, both at the composition surfaces and in the twin axis. We calculate the differences in conformational entropy between chains in single crystals and chains in twinned crystals, and find that the reduction in chain conformational entropy in the twin is sufficient to make the single crystal the stable thermodynamic phase. The formation of cyclic twins in molecular dynamics simulations of chains of hard spheres must thus be attributed to kinetic factors. In more realistic polymers this entropic contribution to the free energy can be canceled or dominated by nonbonded and torsional energetics.

  3. Anaesthesia for the separation of conjoined twins

    Directory of Open Access Journals (Sweden)

    Jaya Lalwani

    2011-01-01

    Full Text Available Thoraco-omphalopagus is one of the most common type of conjoint twins accounting for 74% cases of conjoint twins. We report the anaesthetic management for successful separation of thoraco-omphalopagus conjoint twins, both of them surviving till date. We highlight the responsibility of anaesthesia team in anaesthetising the two individual patients simultaneously, need of careful monitoring and anticipation of complications like massive blood loss, hypotension, hypokalemia, hypoxia and hypercabia. Detailed description of successful management is reported.

  4. Idiopathic intracranial hypertension in female homozygous twins.

    OpenAIRE

    Fujiwara, S; Sawamura, Y; Kato, T.; Abe, H.; Katusima, H

    1997-01-01

    The authors report on female homozygous twins with idiopathic intracranial hypertension. At the age of 12 years, both twins simultaneously developed visual disturbances with photophobia. At the age of 19 years, an ophthalmological examination disclosed papilloedema in both their eyes. At the age of 22 years, a lumbar puncture showed raised CSF pressure over (200 mm H2O) in both twins. Their neurological and radiological examinations were extremely similar; both of them had severely impaired v...

  5. Culture systems: embryo culture and monozygotic twinning.

    Science.gov (United States)

    Sparks, Amy E

    2012-01-01

    The incidence of monozygotic twinning in pregnancies achieved with assisted reproductive technologies (ART) is significantly higher than spontaneously conceived pregnancies. The factors associated with ART that predispose the embryos to splitting are not well-characterized. Assisted hatching and extended embryo culture are two ART laboratory methods that have been risk factors for monozygotic twinning. The methods and strategies that may be employed to avoid monozygotic twinning are discussed in this chapter.

  6. College-age twins: university admission policies / twin research: birth weight and neuromotor performance; transfusion syndrome markers; vanishing twins and fetal sex determination; mz twin discordance for wilson's disease / media: big at birth; planned separation of conjoined twins; x factor twins; Cinema: the identical.

    Science.gov (United States)

    Segal, Nancy L

    2014-12-01

    There is a lack of research findings addressing the unique college admissions issues faced by twins and other multiples. The advantages and disadvantage twins face, as reported by college administrators, twins and families are reviewed. Next, recent research addressing twins' birth weight and neuromotor performance, transfusion syndrome markers, the vanishing twin syndrome and monozygotic (MZ) twin discordance for Wilson's disease is described. News items concerning the birth of unusually large twins, the planned separation of conjoined twins, twin participants in the X Factor games and a film, The Identical, are also summarized.

  7. The Solar Twin Planet Search II. A Jupiter twin around a solar twin

    CERN Document Server

    Bedell, M; Bean, J L; Ramirez, I; Asplund, M; Alves-Brito, A; Casagrande, L; Dreizler, S; Monroe, T; Spina, L; Maia, M Tucci

    2015-01-01

    Through our HARPS radial velocity survey for planets around solar twin stars, we have identified a promising Jupiter twin candidate around the star HIP11915. We characterize this Keplerian signal and investigate its potential origins in stellar activity. Our analysis indicates that HIP11915 hosts a Jupiter-mass planet with a 3600-day orbital period and low eccentricity. Although we cannot definitively rule out an activity cycle interpretation, we find that a planet interpretation is more likely based on a joint analysis of RV and activity index data. The challenges of long-period radial velocity signals addressed in this paper are critical for the ongoing discovery of Jupiter-like exoplanets. If planetary in nature, the signal investigated here represents a very close analog to the solar system in terms of both Sun-like host star and Jupiter-like planet.

  8. How does the inclusion of twins conceived via fertility treatments influence the results of twin studies?

    Science.gov (United States)

    Burt, S Alexandra; Klump, Kelly L

    2012-12-01

    Rates of twinning have risen dramatically over the last 30 years, from 1 in 53 births in 1980 to 1 in 30 births in 2009 (Martin et al. (January 2012). Three decades of twin births in the United States, 1980-2009. Atlanta, GA: Centers for Disease Control and Prevention, National Center for Health Statistics). This increase is largely attributable to increases in the use of fertility treatments (i.e., ovulation induction and in vitro fertilization) combined with delays in parenthood. Although this increase means that more twins are available for recruitment into twin studies, it also has potential consequences for the heritability estimates obtained in these studies. This study sought to evaluate this possibility, making use of the ongoing Michigan Twins Project (N = 7,261 families with twins aged 3-17 years), an arm of the Michigan State University Twin Registry. Results revealed that, on average, twins conceived via fertility treatments had lower rates of behavior problems than those conceived naturally, although these behavioral differences could be explained largely by demographic and socio-economic differences across the two types of twin families. Twin similarity did not meaningfully differ across fertility treatment status. We thus conclude that estimates of genetic and environmental influences obtained from twin studies over the last 10-15 years are more or less unaffected by the inclusion of twins conceived via fertility treatments in their samples.

  9. Rapid onset of severe twin-twin transfusion syndrome caused by placental venous thrombosis

    NARCIS (Netherlands)

    Nikkels, PGJ; van Gemert, MJC; Sollie-Szarynska, KM; Molendijk, H; Timmer, B; Machin, GA

    2002-01-01

    We report a case of rapid onset of severe twin-twin transfusion syndrome (TTTS) at 25 weeks gestation in a monochorionic twin pregnancy that was uneventful before that time. Thrombosis of a main venous branch draining several arteriovenous (AV) anastomoses to the donor changed the previous hemodynam

  10. Atomistic deformation mechanisms in twinned copper nanospheres.

    Science.gov (United States)

    Bian, Jianjun; Niu, Xinrui; Zhang, Hao; Wang, Gangfeng

    2014-01-01

    In the present study, we perform molecular dynamic simulations to investigate the compression response and atomistic deformation mechanisms of twinned nanospheres. The relationship between load and compression depth is calculated for various twin spacing and loading directions. Then, the overall elastic properties and the underlying plastic deformation mechanisms are illuminated. Twin boundaries (TBs) act as obstacles to dislocation motion and lead to strengthening. As the loading direction varies, the plastic deformation transfers from dislocations intersecting with TBs, slipping parallel to TBs, and then to being restrained by TBs. The strengthening of TBs depends strongly on the twin spacing.

  11. Vascular distribution patterns in monochorionic twin placentas.

    Science.gov (United States)

    De Paepe, M E; DeKoninck, P; Friedman, R M

    2005-07-01

    Several recent publications have focused on the association between the occurrence of twin-to-twin transfusion syndrome (TTTS) in diamniotic-monochorionic twins and the presence of a number of selected anatomic placental characteristics (distribution of vascular territory, cord insertion, type and number of inter-twin anastomoses). In contrast, the potential importance of the vascular distribution patterns of the individual twins remains to be elucidated. Based on its gross architectural distribution pattern, chorionic vasculature is traditionally described as disperse, magistral or mixed. The aim of this study was (1) to determine the relative prevalence of these vascular distribution patterns in monochorionic twin placentas, and (2) to correlate these patterns with the presence of TTTS and known anatomic placental features linked to TTTS. The placentas of 89 consecutive diamniotic-monochorionic twins (15 with TTTS, 74 without TTTS), examined at Women and Infants Hospital, were studied. Disperse vascular patterns were seen in 53% of twins, and magistral or mixed patterns in 47%. The prevalence of magistral/mixed vascular patterns was significantly higher in TTTS gestations than in non-TTTS gestations (60% versus 44%, Ppatterns and marginal/velamentous cord insertion, low number of inter-twin anastomoses, and uneven distribution of the vascular territories. These findings suggest that the magistral/mixed vascular distribution pattern may represent an important placental architectural feature contributing to the complex pathophysiology of TTTS.

  12. Invasive treatment in complicated monochorionic twin pregnancies

    DEFF Research Database (Denmark)

    Sundberg, Karin; Søgaard, Kirsten; Jensen, Lisa Neerup;

    2012-01-01

    Objective. Monochorionic twin pregnancies are associated with increased risk of severe complications. Umbilical cord occlusion (UCO) and fetoscopic selective laser coagulation (FSLC) are used as invasive treatment. The study aim was to document treatment indications and pregnancy outcome where UCO...... and FSLC were used for treating fetal discrepancies and twin-to-twin transfusion syndrome (TTTS). Design. Cohort study of all consecutively treated monochorionic twin pregnancies 2004-2010. Setting. Tertiary care center. Population. One hundred and twenty pregnancies treated by FSLC (55) or UCO (65...

  13. Being Pregnant with Twins, Triplets and Other Multiples

    Science.gov (United States)

    ... twins, triplets and other multiples Being pregnant with twins, triplets and other multiples E-mail to a ... embryos that grow into two or more babies. Twins are called identical when one fertilized egg splits ...

  14. Problem in twin pregnancy: Findings of prenatal sonography and autopsy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Ah; Cho, Jeong Yeon; Song, Mi Jin; Min, Jee Yeon; Lee, Young Ho; Lee, Hak Jong; Chun, Yi Kyeong; Kim, Yee Jeong; Hong, Sung Ran [Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2001-12-15

    Multifetal gestations are high risk pregnancies with higher perinatal morbidity and mortality. Multifetal gestations are subject to unique complications including conjoined twins, twin-to-twin transfusion syndrome (TTTS), acardiac twins, twin embization of co-twin demise and heterotopic pregnancies. Prenatal sonographic diagnosis of types and complications of multifetal gestations is important for antenatal care and prediction of fetal outcome. This study was performed to present the prenatal ultrasonographic findings and pathologic findings of the unique complications of twin pregnancy. Acardia is a lethal anomaly occurring in 1% of monozygotic twin. The acardiac twin has a parasitic existence and depends on the donor (pump) twin for its blood supply via placental anastomoses and retrograde perfusion of umbilical cord. This twin reversed arterial perfusion (TRAP) sequence is a most extreme manifestation on the TTTS. Doppler verification reversed flow in umbilical cord of the acardiac twin confirms the diagnosis.

  15. Estimation of Near-Field and Far-Field Dilutions for Site Selection of Effluent Outfall in a Coastal Region - A Case Study

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, V.S.

    location for discharge of the effluents into the sea by using near-field and far-field models. Near-field dilutions were calculated using a buoyant jet model, whereas far-field dilutions were estimated using a two-dimensional numerical model. As a case...

  16. Implementation of the far-field method for calculation of added resistance using a high order finite-difference approximation on overlapping grids

    DEFF Research Database (Denmark)

    Amini Afshar, Mostafa; Bingham, Harry B.

    The far-field method for calculation of the wave drift force is implemented in the high order finitedifferenceseakeeping solver. The implementation is based on the Maruo formulation which employesthe Kochin function to obtain the complex amplitude of the velocity potential in the far-field. There...

  17. Phase Field Modeling of Twinning in Indentation of Transparent Crystals

    Science.gov (United States)

    2011-09-01

    twin boundaries . Equilibrium configurations of deformed and twinned crystals are attained via direct energy minimization. The theory is framed in the...phases: (i) the original crystal (the parent) and (ii) the twin. Interfaces between phases are twin boundaries . Order parameter η generally exhibits the...following values: η(X, •) = 0∀X ∈ parent, = 1∀X ∈ twin, ∈ (0, 1)∀X ∈ twin boundaries . (1) In linear elasticity, kinematic field variables are

  18. Weak phonon scattering effect of twin boundaries on thermal transmission.

    Science.gov (United States)

    Dong, Huicong; Xiao, Jianwei; Melnik, Roderick; Wen, Bin

    2016-01-29

    To study the effect of twin boundaries on thermal transmission, thermal conductivities of twinned diamond with different twin thicknesses have been studied by NEMD simulation. Results indicate that twin boundaries show a weak phonon scattering effect on thermal transmission, which is only caused by the additional twin boundaries' thermal resistance. Moreover, according to phonon kinetic theory, this weak phonon scattering effect of twin boundaries is mainly caused by a slightly reduced average group velocity.

  19. Weak phonon scattering effect of twin boundaries on thermal transmission

    OpenAIRE

    Huicong Dong; Jianwei Xiao; Roderick Melnik; Bin Wen

    2016-01-01

    To study the effect of twin boundaries on thermal transmission, thermal conductivities of twinned diamond with different twin thicknesses have been studied by NEMD simulation. Results indicate that twin boundaries show a weak phonon scattering effect on thermal transmission, which is only caused by the additional twin boundaries’ thermal resistance. Moreover, according to phonon kinetic theory, this weak phonon scattering effect of twin boundaries is mainly caused by a slightly reduced averag...

  20. Far-field characterization of the thermal dynamics in lasing microspheres

    CERN Document Server

    Ramirez, J M; Capuj, N E; Berencen, Y; Pitanti, A; Garrido, B; Tredicucci, A

    2015-01-01

    This work reports the dynamical thermal behavior of lasing microspheres placed on a dielectric substrate while they are homogeneously heated-up by the top-pump laser used to excite the active medium. The lasing modes are collected in the far-field and their temporal spectral traces show characteristic lifetimes of about 2 ms. The latter values scale with the microsphere radius and are independent of the pump power in the studied range. Finite-Element Method simulations reproduce the experimental results, revealing that the thermal dynamics is dominated by the heat dissipated towards the substrate through the medium surrounding the contact point. The characteristic system scale regarding thermal transport is of few hundreds of nanometers, thus enabling an effective toy model for investigating heat conduction in non-continuum gaseous media and near-field radiative energy transfer.

  1. Terminating Ventricular Fibrillation Using Pulsed Far-Field Stimulation in Whole Rabbit Hearts

    Science.gov (United States)

    Squires, Amgad; Hornung, Daniel; Bittihn, Philip; Xia Wu, Dong; Krinsky, Valentin; Zabel, Markus; Bodenschatz, Eberhard; Luther, Stefan

    2010-03-01

    During life-threatening cardiac fibrillation, chaotic spatio-temporal dynamics is mediated by vortex-like rotating waves. Current defibrillation strategies rely on global control through high-energy shocks, which may have severe side-effects including traumatic pain and tissue damage. Far-field antifibrillation pacing terminates fibrillation using a train of low-energy electric pulses [1,2]. Using optical mapping in isolated rabbit heart preparations, we evaluate the efficiency and robustness of this approach. We found that a series of pulses at low energies (ventricular fibrillation with a success rate of 95%. We will discuss the physical mechanisms involved.[4pt] [1] F.H. Fenton et al, Circulation 120 467-476 (2009).[0pt] [2] A. Pumir et al., Phys. Rev. Lett. 99, 208101 (2007).

  2. Single and dual-Gregorian reflector antenna shaped beam far-field synthesis

    Science.gov (United States)

    Mehler, M. J.

    The direct far-field G.O. synthesis of shaped beam reflector antennas has recently been treated by Mehler, Tun and Adatia (1986). These authors use a synthesis technique which exploits complex coordinates and which is based on a method originally considered by Norris and Westcott (1976). They describe the synthesis of single reflector antennas which radiate both elliptical beams and European coverage patterns. Here this technique is extended to consider a class of dual reflector antennas which possess shaped main reflectors and conic subreflectors. An example is given of a Gregorian duel reflector antenna which radiates a cross-polar field significantly smaller than that radiated by single shaped reflector antennas. In addition, the behavior of the radiation pattern as a function of the reflector diameter is investigated.

  3. Far-Field Plasmonic Resonance Enhanced Nano-Particle Image Velocimetry within a Micro Channel

    CERN Document Server

    Zhang, Zhili; Haque, Sara S; Zhang, Mingjun

    2010-01-01

    In this paper, a novel far-field plasmonic resonance enhanced nanoparticle-seeded Particle Image Velocimetry (nPIV) has been demonstrated to measure the velocity profile in a micro channel. Chemically synthesized silver nanoparticles have been used to seed the flow in the micro channel. By using Discrete Dipole Approximation (DDA), plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15nm to 200nm. Optimum scattering wavelength is specified for the nanoparticles in two media: water and air. The diffraction-limited plasmonic resonance enhanced images of silver nanoparticles at different diameters have been recorded and analyzed. By using standard PIV techniques, the velocity profile within the micro channel has been determined from the images.

  4. Far-field nanoscale infrared spectroscopy of vibrational fingerprints of molecules with graphene plasmons

    CERN Document Server

    Hu, Hai; Zhai, Feng; Hu, Debo; Liu, Ruina; Liu, Kaihui; Sun, Zhipei; Dai, Qing

    2016-01-01

    Infrared spectroscopy, especially for molecular vibrations in the fingerprint region between 600 and 1500 cm-1, is a powerful characterization method for bulk materials. However, molecular fingerprinting at the nanoscale level still remains a significant challenge, due to weak light-matter interaction between micron-wavelengthed infrared light and nano-sized molecules. Here, we demonstrate molecular fingerprinting at the nanoscale level using our specially designed graphene plasmonic structure on CaF2 nanofilm. This structure not only avoids the plasmon-phonon hybridization, but also provides in situ electrically-tunable graphene plasmon covering the entire infrared fingerprint region, which was previously unattainable. In addition, undisturbed and highly-confined graphene plasmon offers simultaneous detection of in-plane and out-of-plane vibrational modes with ultrahigh detection sensitivity down to the sub-monolayer level, significantly pushing the current detection limit of far-field mid-infrared spectrosc...

  5. Multifunctional microscope for far-field and tip-enhanced Raman spectroscopy

    Science.gov (United States)

    Vannier, Christophe; Yeo, Boon-Siang; Melanson, Jeremy; Zenobi, Renato

    2006-02-01

    The development of a versatile and easy-to-use instrument designed for Raman micro- and nanospectroscopy in the visible range is described in this work. An atomic force microscope, an inverted confocal microscope, and a piezostage are combined to perform an accurate and fast tip-laser alignment and to characterize large areas under the same conditions of illumination across the surface. In addition, a metallized tip is used to locally enhance the electromagnetic field and to probe the sample surface leading to in situ chemical analysis at the nanoscale. Both far-field and tip-enhanced Raman spectroscopies (TERS) have been carried out on dye molecules and on nano-objects with short exposure times. The TERS observation of tip-induced sample deformation on single-walled carbon nanotubes is also presented.

  6. Optical far-field super-resolution microscopy using nitrogen vacancy center ensemble in bulk diamond

    Science.gov (United States)

    Li, Shen; Chen, Xiang-dong; Zhao, Bo-Wen; Dong, Yang; Zou, Chong-Wen; Guo, Guang-Can; Sun, Fang-Wen

    2016-09-01

    We demonstrate optical far-field super-resolution microscopy using an array of nitrogen vacancy centers in bulk diamond as near-field optical probes. The local optical field, which transmits through the nanostructures on the diamond surface, is measured by detecting the charge state conversion of the nitrogen vacancy center. Locating the nitrogen vacancy center with a spatial resolution of 6.1 nm is realized with charge state depletion nanoscopy. The nanostructures on the surface of a diamond are then imaged with a resolution below the optical diffraction limit. The results offer an approach to build a general-purpose optical super-resolution microscopy technique and a convenient platform for high spatial resolution quantum sensing with nitrogen vacancy centers.

  7. Spatial frequency characterisation of a far-field superlens to facilitate general purpose imaging

    Science.gov (United States)

    Fadakar Masouleh, Farzaneh; Teal, Paul; Moore, Ciaran

    2016-04-01

    Based on sub-wavelength energy concentration and enhancement of evanescent fields, far-field super-lenses (FSLs) were proposed recently as a means to achieve super-resolution imaging and thus improve the accuracy and resolution of optical microscopy. Comprised of a thin-film plasmonic enhancement layer and a diffraction grating, the performance of FSLs depends greatly on the geometry and size of its constituent parts. In this paper, we aim to characterize the resolution capabilities of FSLs in a novel and meaningful way, while also exploring the effects of non-ideal grating geometries due to fabrication limitations on imaging performance. We use finite element modelling to explore trapezoidal, inverse-trapezoidal, circular, rounded rectangular, and rectangular grating profiles and present a transfer function that quantifies the performance of these grating profiles in terms of their transmission at different wavenumbers.

  8. Far-field and near-field investigation of plasmonic-photonic hybrid laser mode

    CERN Document Server

    Zhang, Taiping; Callard, Ségolène; jamois, Cecile; Letartre, Xavier; Chevalier, Celine; Rojo-Romeo, Pedro; Devif, Brice; Viktorovitch, Pierre

    2014-01-01

    We report an approach to achieve this goal via build a plasmonic-dielectric photonic hybrid system. We induce a defect mode based photonic crystal (PC) cavity to work as a intermedium storage as well as a near-field light source to excite a plasmonic nanoantenna (NA). In this way, a plasmonic-photonic nano-laser source is created in present experiment. The coupling condition between the two elements is investigated in far-field and near-field level. We found that the NA reduces the Q-factor of the PC-cavity. Meanwhile, the NA concentrates and enhances the laser emission of the PC-cavity. This novel hybrid dielectric-plasmonic structure may open a new avenue in the generation of nano-light sources, which can be applied in areas such as optical information storage, non-linear optics, optical trapping and detection, integrated optics, etc.

  9. Image restoration for indirectly far-field image using microlenses array integrated with LCD

    Science.gov (United States)

    Yang, Fugui; Wang, Anting; Lei, Dong; Zhe, Cui; Ming, Hai

    2010-10-01

    Image restoration for constructing high-spatial-resolution images in an imaging system which realizes indirectly far-filed imaging by integrating the microlenses array with LCD is reported. We have investigated the indirectly far-field imaging condition where adjacent sampling points contribute the detected signal. Experimental setup with microlens of 500 μm diameter and 8 mm focal length is built to prove this condition by studying performance of image restoration using modified point spread function (PSF). Since any one iterative method is not optimal for all image deblurring problems, some deblurring algorithms including direct deconvolution and iterative deconvolution are applied to our imaging system and we compared the effectiveness of these iterative procedures to choose right one for our use.

  10. Near- and far-field properties of plasmonic oligomers under radially and azimuthally polarized light excitation.

    Science.gov (United States)

    Yanai, Avner; Grajower, Meir; Lerman, Gilad M; Hentschel, Mario; Giessen, Harald; Levy, Uriel

    2014-05-27

    We present a comprehensive experimental and theoretical study on the near- and far-field properties of plasmonic oligomers using radially and azimuthally polarized excitation. These unconventional polarization states are perfectly matched to the high spatial symmetry of the oligomers and thus allow for the excitation of some of the highly symmetric eigenmodes of the structures, which cannot be excited by linearly polarized light. In particular, we study hexamer and heptamer structures and strikingly find very similar optical responses, as well as the absence of a Fano resonance. Furthermore, we investigate the near-field distributions of the oligomers using near-field scanning optical microscopy (NSOM). We observe significantly enhanced near-fields, which arise from efficient excitation of the highly symmetric eigenmodes by the radially and azimuthally polarized light fields. Our study opens up possibilities for tailored light-matter interaction, combining the design freedom of complex plasmonic structures with the remarkable properties of radially and azimuthally polarized light fields.

  11. Optical far-field super-resolution microscopy using nitrogen vacancy center ensemble in bulk diamond

    CERN Document Server

    Li, Shen; Zhao, Bo-Wen; Dong, Yang; Zou, Chong-Wen; Guo, Guang-Can; Sun, Fang-Wen

    2016-01-01

    We demonstrate an optical far-field super-resolution microscopy using array of nitrogen vacancy centers in bulk diamond as near-field optical probes. The local optical field, which transmits through the nanostructures on the diamond surface, is measured by detecting the charge state conversion of nitrogen vacancy center. And the locating of nitrogen vacancy center with spatial resolution of 6.1 nm is realized with the charge state depletion nanoscopy. The nanostructures on the surface of diamond are then imaged with resolution below optical diffraction limit. The results offer an approach to built a general-purpose optical super-resolution microscopy and a convenient platform for high spatial resolution quantum sensing with nitrogen vacancy center.

  12. Planar Near-Field Phase Retrieval Using GPUs for Accurate THz Far-Field Prediction

    Science.gov (United States)

    Junkin, Gary

    2013-04-01

    With a view to using Phase Retrieval to accurately predict Terahertz antenna far-field from near-field intensity measurements, this paper reports on three fundamental advances that achieve very low algorithmic error penalties. The first is a new Gaussian beam analysis that provides accurate initial complex aperture estimates including defocus and astigmatic phase errors, based only on first and second moment calculations. The second is a powerful noise tolerant near-field Phase Retrieval algorithm that combines Anderson's Plane-to-Plane (PTP) with Fienup's Hybrid-Input-Output (HIO) and Successive Over-Relaxation (SOR) to achieve increased accuracy at reduced scan separations. The third advance employs teraflop Graphical Processing Units (GPUs) to achieve practically real time near-field phase retrieval and to obtain the optimum aperture constraint without any a priori information.

  13. An atmospheric backscatter model on wind measurements using far-field approximation method

    Institute of Scientific and Technical Information of China (English)

    SHU Weiping; ZHAO Zhengyu

    2007-01-01

    A backscatter model was developed for measuring wind field with the far-field approximation method.The theoretical computation and computer simulations with one spatial dimension show that this model can realistically describe the physical meaning and process of the three methods in wind measurements including the spaced antenna (SA) method,Doppler beam swing (DBS) method,and spaced interferometry (SI).The computational difficulties of the traditional theoretical model cannot only be smoothed away,but common characteristics and differences of the three methods can be compared deeply.The comparison of the numerical results between the Wuhan medium frequency (MF) radar (30° N,114° E) observation and the computer simulation of the full correlation analysis (FCA) of the SA method indicates that the two results agree very well and this model has practical application.

  14. Thermal extraction: enhancing thermal emission of finite size macroscopic blackbody to far-field vacuum

    CERN Document Server

    Yu, Zongfu; Zhang, Torbjorn Skauli Gang; Wang, Hailiang; Fan, Shanhui

    2012-01-01

    The understanding of far-field thermal radiation had directly led to the discovery of quantum mechanics a century ago, and is of great current practical importance for applications in energy conversions, radiative cooling, and thermal control. It is commonly assumed that for any macroscopic thermal emitter, its maximal emitted power within any given frequency range cannot exceed that of a blackbody with the same surface area. In contrast to such conventional wisdom, here we propose, and experimentally demonstrate, that the emitted power from a finite size macroscopic blackbody to far field vacuum can be significantly enhanced, within the constraint of the second law of thermodynamics. To achieve such an enhancement, the thermal body needs to have internal electromagnetic density of states (DOS) greater than that of vacuum, and one needs to provide a thermal extraction mechanism to enable the contributions of all internal modes to far field radiation.

  15. Far-Field Distributions of Double-Heterostructure Diode Lasers: an Improved Non-Equiphase Model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhi-Guo; DUAN Kai-Liang; LU Bai-Da

    2007-01-01

    A non-equiphase Gaussian model is proposed to simulate the far-field distributions ofdouble-heterostructure diode lasers, which is physically reasonable because the phase along the junction of diode lasers could not be equal. A comparison of the numerically calculated intensity profiles in using the equal phase and non-equiphase models with the experimentally measured intensity profiles given by Nemoto shows that in the x direction perpendicular to the junction plane, the non-equiphase Gaussian model is as good as the equal phase Gaussian model. Specifically,in the y direction parallel to the junction plane and the 45° direction with respect to the x axis in the xoy plane,the numerical results by using the non-equiphase model are in good agreement with the experimental data, as the propagation distance is larger than a certain value.

  16. The state of the art of twinning, a concept analysis of twinning in healthcare.

    Science.gov (United States)

    Cadée, Franka; Nieuwenhuijze, Marianne J; Lagro-Janssen, A L M; De Vries, Raymond

    2016-10-26

    Inequities in health have garnered international attention and are now addressed in Sustainable Development Goal 3 (SDG3), which seeks to 'promote well-being for all'. To attain this goal globally requires innovative approaches, one of which is twinning. According to the International Confederation of Midwives, twinning focusses on empowering professionals, who can subsequently be change-agents for their communities. However, twinning in healthcare is relatively new and because the definition and understanding of twinning lacks clarity, rigorous monitoring and evaluation are rare. A clear definition of twinning is essential for the development of a scientific base for this promising form of collaboration. We conducted a Concept Analysis (CA) of twinning in healthcare using Morse's method. A qualitative study of the broad literature was performed, including scientific papers, manuals, project reports, and websites. We identified relevant papers through a systematic search using scientific databases, backtracking of references, and experts in the field. We found nineteen papers on twinning in healthcare. This included twelve peer reviewed research papers, four manuals on twinning, two project reports, and one website. Seven of these papers offered no definition of twinning. In the other twelve papers definitions varied. Our CA of the literature resulted in four main attributes of twinning in healthcare. First, and most frequently mentioned, was reciprocity. The other three attributes were that twinning: 2) entails the building of personal relationships, 3) is dynamic process, 4) is between two named organisations across different cultures. The literature also indicated that these four attributes, and especially reciprocity, can have an empowering effect on healthcare professionals. Based on these four attributes we developed the following operational definition: Twinning is a cross-cultural, reciprocal process where two groups of people work together to achieve joint

  17. [Social development of twins: the need for intervention to avoid adverse effects of twin language].

    Science.gov (United States)

    Hayashi, Chisato; Hayakawa, Kazuo; Maeda, Chiho; Nishihara, Reiko; Onoi, Miyuki

    2008-10-01

    Social competence is one of the most important accomplishments of human development, and this skill in human relationships is learned through communication. Therefore, it is considered that delays in language development could be a barrier to building human relationships and social competence. Although it is well known that there are delays in language development in twins compared with that of singletons, little is known about how these linguistic delays affect the development of social competence. Because twin language is a language that is unique to each pair of twins and cannot be understood by either their mother or others, it may be assumed that the social competence of twins who have a twin language is less than that of twins who don't have a twin language. Therefore, in this prospective longitudinal study we also investigated the relationship between twin language and social competence. A mailed questionnaire survey was conducted in 958 mothers as a follow-up of a study conducted in 2004. As a result, 522 respondents returned the questionnaire (53.9%). In this study, we used only 256 twins aged 6- 12-years-old (school-age children) for analysis, excluding those with missing values. Multiple logistic regression analysis was employed. In the second child of twins, a low birth weight, the appearance of twin language and gestosis of the mother were positively related with social unbalance (OR = 1.846, 2.022 and 1.903). On the other hand, with the first child, however, there was no such link. The present results indicate that twin language might influence social competence in school-age children. It has been believed that linguistic intervention is unnecessary, because most twin language disappears spontaneously. However, early intervention, for example linguistic assistance by public health nurses or psychologists and early enrollment in a preschool may be necessary for twins with a twin language, to avoid adverse consequences in social competence at school-age.

  18. The role of farfield tectonic stress in oceanic intraplate deformation, Gulf of Alaska

    Science.gov (United States)

    Reece, Robert S.; Gulick, Sean P. S.; Christesen, Gail L.; Horton, Brian K.; VanAvendonk, Harm J.; Barth, Ginger

    2013-01-01

    An integration of geophysical data from the Pacific Plate reveals plate bending anomalies, massive intraplate shearing and deformation, and a lack of oceanic crust magnetic lineaments in different regions across the Gulf of Alaska. We argue that farfield stress from the Yakutat Terrane collision with North America is the major driver for these unusual features. Similar plate motion vectors indicate that the Pacific plate and Yakutat Terrane are largely coupled along their boundary, the Transition Fault, with minimal translation. Our study shows that the Pacific Plate subduction angle shallows toward the Yakutat Terrane and supports the theory that the Pacific Plate and Yakutat Terranemaintain coupling along the subducted region of the Transition Fault. We argue that the outboard transfer of collisional stress to the Pacific Plate could have resulted in significant strain in the NE corner of the Pacific Plate, which created pathways for igneous sill formation just above the Pacific Plate crust in the Surveyor Fan. A shift in Pacific Plate motion during the late Miocene altered the Yakutat collision with North America, changing the stress transfer regime and potentially terminating associated strain in the NE corner of the Pacific Plate. The collision further intensified as the thickest portion of the Yakutat Terrane began to subduct during the Pleistocene, possibly providing the impetus for the creation of the Gulf of Alaska Shear Zone, a>200 km zone of intraplate strike-slip faults that extend from the Transition Fault out into the Pacific Plate. This study highlights the importance of farfield stress from complex tectonic regimes in consideration of large-scale oceanic intraplate deformation.

  19. Modeling of coastal effluent transport: an approach to linking far-field and near-field models

    Institute of Scientific and Technical Information of China (English)

    YANG Zhaoqing; KHANGAOKAR Tarang

    2008-01-01

    One of the challenges in effluent transport modeling in coastal tidal environments is the proper specification of initial dilution in connection with the far-field transport phenomena. An approach of external linkage of far-field and near-field effluent transport models is presented, and applied to simulating the effluent transport in the Port Angeles Harbor, Washington in the Strait of Juan de Fuea. A near-field plume model was used to calculate the effluent initial dilution and a three-dimensional (3-D) hydrodynamic model was developed to simulate the tidal circulation and far-field effluent transport in the Port Angeles Harbor. The hydrodynamic model was driven by tides and surface winds. Observed water surface elevation and velocity data were used to calibrate the model over a period covering the neap-spring tidal cycle. The model was also validated with observed surface drogue trajectory data. The model successfully reproduced the tidal dynamics in the study area and good agreements between model results and observed data were obtained. It is demonstrated that the linkage between the near-field and far-field models in effluent transport modeling can be achieved through iteratively adjusting the model grid sizes such that the dilution ratio and effluent concentration in the circulation model grid cell match the concentration calculated by the near-field plume model.

  20. Sustained lobe reconnection in Saturn's magnetotail

    Science.gov (United States)

    Thomsen, M. F.; Jackman, C. M.; Mitchell, D. G.; Hospodarsky, G.; Kurth, W. S.; Hansen, K. C.

    2015-12-01

    The degree to which solar wind driving may affect Saturn's magnetosphere is not yet fully understood. We present observations that suggest that under some conditions the solar wind does govern the character of the plasma sheet in Saturn's outer magnetosphere. On 16 September 2006, the Cassini spacecraft, at a radial distance of 37 Rs near local midnight, observed a sunward flowing ion population for ~5 h, which was accompanied by enhanced Saturn Kilometric Radiation emissions. We interpret this beam as the outflow from a long-lasting episode of Dungey-type reconnection, i.e., reconnection of previously open flux containing magnetosheath material. The beam occurred in the middle of a several-day interval of SKR activity and enhanced lobe magnetic field strength, apparently caused by the arrival of a solar wind compression region with significantly higher than average dynamic pressure. The arrival of the high-pressure solar wind also marked a change in the composition of the plasma-sheet plasma, from water-group-dominated material clearly of inner-magnetosphere origin to material dominated by light-ion composition, consistent with captured magnetosheath plasma. This event suggests that under the influence of prolonged high solar wind dynamic pressure, the tail plasma sheet, which normally consists of inner-magnetospheric plasma, is eroded away by ongoing reconnection that then involves open lobe field lines. This process removes open magnetic flux from the lobes and creates a more Earth-like, Dungey-style outer plasma sheet dominantly of solar wind origin. This behavior is potentially a recurrent phenomenon driven by repeating high-pressure streams (corotating interaction regions) in the solar wind, which also drive geomagnetic storms at Earth.

  1. Haemodynamic resistance model of monochorionic twin pregnancies complicated by acardiac twinning

    Energy Technology Data Exchange (ETDEWEB)

    Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam(Netherlands); Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Ross, Michael G [Department of Obstetrics and Gynecology, Harbor University of California-Los Angeles Medical Center, Torrence, CA 9050 (United States); Nikkels, Peter G J [Department of Pathology, University Medical Center, Utrecht (Netherlands)

    2004-07-21

    An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauterine or neonatally in about 50% of the cases due to congestive heart failure, polyhydramnios and prematurity. Because the pathophysiology of this pregnancy is currently incompletely understood, we modified our previous haemodynamic model of monochorionic twins connected by placental vascular anastomoses to include the analysis of acardiac twin pregnancies. We incorporated the fetoplacental circulation as a resistance circuit and used the fetal umbilical flow that perfuses the body to define fetal growth, rather than the placental flow as done previously. Using this modified model, we predicted that the pump twin has excess blood volume and increased mean arterial blood pressure compared to those in the acardiac twin. Placental perfusion of the acardiac twin is significantly reduced compared to normal, as a consequence of an increased venous pressure, possibly implying reduced acardiac placental growth. In conclusion, the haemodynamic analysis may contribute to an increased knowledge of the pathophysiologic consequences of an acardiac body mass for the pump twin. (note)

  2. Vascular programming in twins: the effects of chorionicity and fetal therapy for twin-to-twin transfusion syndrome.

    Science.gov (United States)

    Gardiner, H M; Barlas, A; Matsui, H; Diemert, A; Taylor, M J O; Preece, J; Gordon, F; Greenwald, S E; Hecher, K

    2012-06-01

    We assessed vascular programming in genetically identical monochorionic twin pairs with twin-to-twin transfusion syndrome (TTTS) treated differently in utero by serial amnioreduction or fetal laser arterial photocoagulation. This case-control study re-assessed four twin groups at median 11 years comprising 20 pairs of monochorionic diamniotic twins: nine treated by amnioreduction (TTTS-amnio) and eleven by laser (TTTS-laser) with seven monochorionic and six dichorionic control pairs. Outcome measures were current blood pressure (BP), brachio-radial arterial stiffness derived from pulse wave velocity (PWV), resting microcirculation (Flux) and response to heating and post-occlusive reactive hyperaemia measured using laser Doppler. Potential confounders [PWV and BP at first study, current height, weight, heart rate and twin type (ex-recipient, ex-donor or heavier/lighter of pair)] were accounted for by Mixed Linear Models statistical methodology. PWV dichorionic > monochorionic (P = 0.024); systolic and diastolic BP dichorionic > TTTS-amnio and TTTS-laser (P = 0.004, P = 0.02 and P = 0.005, P = 0.02, respectively). Within-twin pair pattern of PWV discordance was similar in laser treated and dichorionic controls (heavier-born > lighter), opposite to TTTS-amnio and monochorionic controls. Flux monochorionic > dichorionic (P = 0.044) and heavier > lighter-born (P = 0.024). TTTS-laser and dichorionic diamniotic showed greatest hyperaemic responses (dichorionic > TTTS-amnio or monochorionic controls (P = 0.007, P = 0.025). Hyperaemic responses were slower in heavier-born twins (P = 0.005). In summary, monochorionic twins had lower BP, arterial stiffness and increased resting vasodilatation than dichorionic twins implying shared fetal circulation affects vascular development. Vascular responses in laser-TTTS were similar to dichorionic and opposite to TTTS-amnio suggesting a lasting effect of fetal therapy on vascular health.

  3. Twin-Foucault imaging method

    Science.gov (United States)

    Harada, Ken

    2012-02-01

    A method of Lorentz electron microscopy, which enables observation two Foucault images simultaneously by using an electron biprism instead of an objective aperture, was developed. The electron biprism is installed between two electron beams deflected by 180° magnetic domains. Potential applied to the biprism deflects the two electron beams further, and two Foucault images with reversed contrast are then obtained in one visual field. The twin Foucault images are able to extract the magnetic domain structures and to reconstruct an ordinary electron micrograph. The developed Foucault method was demonstrated with a 180° domain structure of manganite La0.825Sr0.175MnO3.

  4. Fatique life and twinning in alphazirconium

    DEFF Research Database (Denmark)

    Warren, M.R.; Beevers, C.J.

    1970-01-01

    stress for {11−21} twinning of ~0.5 kg mm−2 in zirconium containing 0.003 wt pct O. During observations confined to internal grains it was found that increasing grain size and decreasing oxygen content favored the formation of fatigue damage in association with these {11−21} twins. In external grains...

  5. Fetal behavior in normal dichorionic twin pregnancy

    NARCIS (Netherlands)

    Mulder, E. J. H.; Derks, J. B.; de Laat, M. W. M.; Visser, G. H. A.

    2012-01-01

    Objectives: A prospective study was performed to compare fetal behavioral development in healthy dichorionic twins and singletons, and identify twin intra-pair associations (synchrony) of fetal movements and rest-activity cycles using different criteria to define synchrony. Subjects and methods: Twe

  6. A Danish Twin Study of Schizophrenia Liability

    DEFF Research Database (Denmark)

    Kläning, Ulla; Trumbetta, Susan L; Gottesman, Irving I

    2016-01-01

    We studied schizophrenia liability in a Danish population-based sample of 44 twin pairs (13 MZ, 31 DZ, SS plus OS) in order to replicate previous twin study findings using contemporary diagnostic criteria, to examine genetic liability shared between schizophrenia and other disorders, and to explo...

  7. Colorado Longitudinal Twin Study of Reading Disability

    Science.gov (United States)

    Wadsworth, Sally J.; DeFries, John C.; Olson, Richard K.; Willcutt, Erik G.

    2007-01-01

    The primary objectives of the present study are to introduce the Colorado Longitudinal Twin Study of Reading Disability, the first longitudinal twin study in which subjects have been specifically selected for having a history of reading difficulties, and to present some initial assessments of the stability of reading performance and cognitive…

  8. Cord entanglement in monoamniotic twin pregnancies

    DEFF Research Database (Denmark)

    Lyndrup, J; Schouenborg, Lars Øland

    1987-01-01

    Monoamniotic twin pregnancy involves a heavy risk of fatal umbilical cord entanglement. Two cases are reported. In the first case, both twins were found dead in the 36th week, and the monoamnionicity was recognized at birth. In the second case, the monoamnionicity was discovered during...

  9. Optimal nutrition for improved twin pregnancy outcome.

    Science.gov (United States)

    Goodnight, William; Newman, Roger

    2009-11-01

    Twin pregnancies contribute a disproportionate degree to perinatal morbidity, partly because of increased risks of low birth weight and prematurity. Although the cause of the morbidity is multifactorial, attention to twin-specific maternal nutrition may be beneficial in achieving optimal fetal growth and birth weight. Achievement of body mass index (BMI)-specific weight gain goals, micronutrient and macronutrient supplementation specific to the physiology of twin gestations, and carbohydrate-controlled diets are recommended for optimal twin growth and pregnancy outcomes. The daily recommended caloric intake for normal-BMI women with twins is 40-45 kcal/kg each day, and iron, folate, calcium, magnesium, and zinc supplementation is recommended beyond a usual prenatal vitamin. Daily supplementation of docosahexaenoic acid and vitamin D should also be considered. Multiple gestation-specific prenatal care settings with a focus on nutritional interventions improve birth weight and length of gestation and should be considered for the care of women carrying multiples. Antepartum lactation consultation can also improve the rate of postpartum breastfeeding in twin pregnancies. Twin gestation-specific nutritional interventions seem effective in improving the outcome of these pregnancies and should be emphasized in the antepartum care of multiple gestations. This review examines the available evidence and offers recommendations for twin pregnancy-specific nutritional interventions.

  10. Twin-Screw Extruders in Ceramic Extrusion

    Science.gov (United States)

    Wiedmann, Werner; Hölzel, Maria

    The machines mainly used for compounding plastics, chemicals and food are co-rotating, closely intermeshing twin-screw extruders. Some 30 000 such extruders are in use worldwide, about 1/3 are ZSKs from Coperion Werner & Pfleiderer, Stuttgart. In the chemical industry more and more batch mixers are being replaced by continuous twin-screw kneaders.

  11. Antisaccade generation is impaired after parietal lobe lesions.

    Science.gov (United States)

    Sharpe, James A; Cheng, Ping; Eizenman, Moshe

    2011-09-01

    Antisaccades are directed away from visual targets. Impaired antisaccade generation has been attributed to frontal lobe damage. We studied antisaccades in patients with unilateral focal parietal lobe lesions. Normal subjects (N = 10) instructed to make 10° antisaccades opposite to a 100-ms target flash 10° to the right or left of center made antisaccades in 86.1% of trials. Patients (N = 13) made antisaccades contraversive to their lesions in 55.4% of trials and 50.5% of ipsiversive trials. In other trials, reflexive saccades occurred toward the target flash. Nine patients with imaged lesions overlapping in parietal lobe white matter showed subnormal antisaccade generation. Antisaccades provide a means of measuring voluntary saccade function of the parietal lobes independent of visual guidance. Impaired suppression of reflexive saccades and generation of antisaccades is attributed to disconnection of parietal lobe from frontal lobe ocular motor areas. © 2011 New York Academy of Sciences.

  12. Is the parietal lobe necessary for recollection in humans?

    Science.gov (United States)

    Simons, Jon S; Peers, Polly V; Hwang, David Y; Ally, Brandon A; Fletcher, Paul C; Budson, Andrew E

    2008-03-07

    An intriguing puzzle in cognitive neuroscience over recent years has been the common observation of parietal lobe activation in functional neuroimaging studies during the performance of human memory tasks. These findings have surprised scientists and clinicians because they challenge decades of established thinking that the parietal lobe does not support memory function. However, direct empirical investigation of whether circumscribed parietal lobe lesions might indeed be associated with human memory impairment has been lacking. Here we confirm using functional magnetic resonance imaging that significant parietal lobe activation is observed in healthy volunteers during a task assessing recollection of the context in which events previously occurred. However, patients with parietal lobe lesions that overlap closely with the regions activated in the healthy volunteers nevertheless exhibit normal performance on the same recollection task. Thus, although the processes subserved by the human parietal lobe appear to be recruited to support memory function, they are not a necessary requirement for accurate remembering to occur.

  13. Utilizing twins as controls for non-twin case-materials in genome wide association studies.

    Directory of Open Access Journals (Sweden)

    Andrea Ganna

    Full Text Available Twin registries around the globe have collected DNA samples from large numbers of monozygotic and dizygotic twins. The twin sample collections are frequently used as controls in disease-specific studies together with non-twins. This approach is unbiased under the hypothesis that twins and singletons are comparable in terms of allele frequencies; i.e. there are no genetic variants associated with being a twin per se. To test this hypothesis we performed a genome-wide association study comparing the allele frequency of 572,352 single nucleotide polymorphisms (SNPs in 1,413 monozygotic (MZ and 5,451 dizygotic (DZ twins with 3,720 healthy singletons. Twins and singletons have been genotyped using the same platform. SNPs showing association with being a twin at P-value < 1 × 10(-5 were selected for replication analysis in 1,492 twins (463 MZ and 1,029 DZ and 1,880 singletons from Finland. No SNPs reached genome-wide significance (P-value < 5 × 10(-8 in the main analysis combining MZ and DZ twins. In a secondary analysis including only DZ twins two SNPs (rs2033541 close to ADAMTSL1 and rs4149283 close to ABCA1 were genome-wide significant after meta-analysis with the Finnish population. The estimated proportion of variance on the liability scale explained by all SNPs was 0.08 (P-value=0.003 when MZ and DZ were considered together and smaller for MZ (0.06, P-value=0.10 compared to DZ (0.09, P-value=0.003 when analyzed separately. In conclusion, twins and singletons can be used in genetic studies together with general population samples without introducing large bias. Further research is needed to explore genetic variances associated with DZ twinning.

  14. OCCIPITAL LOBE EPILEPSY OR MIGRAINE HEADACHE

    Directory of Open Access Journals (Sweden)

    Skrijelj Fadil E

    2016-12-01

    Full Text Available Introduction: Occipital lobe epilepsies are rarely met in clinical practice, but when they occur, they can be misdiagnosed as migraine-like headache. Their prevalence ranges from 5%to 10% of all epilepsies. Seizures can occur at any age; etiologically speaking they can be symptomatic, cryptogenic and idiopathic (most often onsetis in childhood. Clinical symptomatology is manifested by partial epileptic seizures in the sense of visual elementary and/or complex manifestations, palinopsia, amaurosis, tonic head deviation, bulbus, nistagmus and headache. Propagation discharge to neighbour areas (temporal, parietal and frontal is a frequent occurrence appearing with complex partial seizures frequently finishing with secondary generalized tonic-clonic (GTC seizures. Case report: We are presenting a17-year-old male patient who has suffered from attacks of visual problemswith headache since 10 years of age. All the time it is treated as a migraine headache. During the last attack of headache the patient also had a loss of consciousness, EEG that was performed for the first time evidenced epileptic discharges of the occipital area. The therapy also included treatment with antiepileptic drug pregabalin resulting in seizure withdrawal. Conclusion: The appearance of visual symptoms followed by headache is most frequently qualified as migraine triggered headache. However, when antimigraine therapy does not give favorable results epileptic headache should be suspected, with obligatory performance of EEG recording. Occipital lobe epilepsy often presents diagnostic dilemmas due to clinical manifestations that are similar to that of non-migraine headache.

  15. [Normal aging of frontal lobe functions].

    Science.gov (United States)

    Calso, Cristina; Besnard, Jérémy; Allain, Philippe

    2016-03-01

    Normal aging in individuals is often associated with morphological, metabolic and cognitive changes, which particularly concern the cerebral frontal regions. Starting from the "frontal lobe hypothesis of cognitive aging" (West, 1996), the present review is based on the neuroanatomical model developed by Stuss (2008), introducing four categories of frontal lobe functions: executive control, behavioural and emotional self-regulation and decision-making, energization and meta-cognitive functions. The selected studies only address the changes of one at least of these functions. The results suggest a deterioration of several cognitive frontal abilities in normal aging: flexibility, inhibition, planning, verbal fluency, implicit decision-making, second-order and affective theory of mind. Normal aging seems also to be characterised by a general reduction in processing speed observed during neuropsychological assessment (Salthouse, 1996). Nevertheless many cognitive functions remain preserved such as automatic or non-conscious inhibition, specific capacities of flexibility and first-order theory of mind. Therefore normal aging doesn't seem to be associated with a global cognitive decline but rather with a selective change in some frontal systems, conclusion which should be taken into account for designing caring programs in normal aging.

  16. 'Biracial'-Looking Twins: A New Twin Type?/Twin Research: Twins with Cystic Teratomas; Sleep Quality and Body Mass Index; Previable Membrane Rupture/Print and Online Reports: Twins Born to a Sister Surrogate; NASA Twin Study; African-Cosmopolitan Twin Fashion Inspirations; Triplet Hockey Stars.

    Science.gov (United States)

    Segal, Nancy L

    2017-06-01

    Dizygotic (DZ) co-twins born to mothers and fathers from different racial or ethnic backgrounds often resemble one parent much more than the other. As such, these pairs comprise a unique subset of twins for investigating how others' responses to their different looks may affect their personalities and self-esteem. This article describes some of these twin pairs and some challenges of raising them, and suggests ways they may be used in research. Next, recent twin research on cystic teratomas, relations between sleep quality and body mass index, and previable membrane rupture is described. The final section concerns twins, twin studies, and related events in the media, namely: twins born to a sister surrogate, the NASA twin investigation, inspiring African-Cosmopolitan twins in fashion, and triplet Hockey Stars.

  17. Twins in Ancient Greece: a synopsis.

    Science.gov (United States)

    Malamitsi-Puchner, Ariadne

    2016-01-01

    This brief outline associates twins with several aspects of life in Ancient Greece. In Greek mythology twins caused ambivalent reactions and were believed to have ambivalent feelings for each other. Very often, they were viewed as the representatives of the dualistic nature of the universe. Heteropaternal superfecundation, which dominates in ancient myths, explains on one hand, the god-like qualities and, on the other hand, the mortal nature of many twins. An assumption is presented that legends referring to twins might reflect the territorial expansions of Ancient Greeks in Northern Mediterranean, around the Black Sea, in Asia Minor, as well as North East Africa. In conclusion, in Greek antiquity, twins have been used as transitional figures between myth and reality.

  18. Cosmological Signals of a Mirror Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Trott, Timothy

    2016-01-01

    We investigate the cosmology of the minimal model of neutral naturalness, the mirror Twin Higgs. The softly-broken mirror symmetry relating the Standard Model to its twin counterpart leads to significant dark radiation in tension with BBN and CMB observations. We quantify this tension and illustrate how it can be mitigated in several simple scenarios that alter the relative energy densities of the two sectors while respecting the softly-broken mirror symmetry. In particular, we consider both the out-of-equilibrium decay of a new scalar as well as reheating in a toy model of twinned inflation, Twinflation. In both cases the dilution of energy density in the twin sector does not merely reconcile the existence of a mirror Twin Higgs with cosmological constraints, but predicts contributions to cosmological observables that may be probed in current and future CMB experiments. This raises the prospect of discovering evidence of neutral naturalness through cosmology rather than colliders.

  19. Highlights from the 15th International Congress of Twin Studies/Twin Research: Differentiating MZ Co-twins Via SNPs; Mistaken Infant Twin-Singleton Hospital Registration; Narcolepsy With Cataplexy; Hearing Loss and Language Learning/Media Mentions: Broadway Musical Recalls Conjoined Hilton Twins; High Fashion Pair; Twins Turn 102; Insights From a Conjoined Twin Survivor.

    Science.gov (United States)

    Segal, Nancy L

    2015-02-01

    Highlights from the 15th International Congress of Twin Studies are presented. The congress was held November 16-19, 2014 in Budapest, Hungary. This report is followed by summaries of research addressing the differentiation of MZ co-twins by single nucleotide polymorphisms (SNPs), an unusual error in infant twin-singleton hospital registration, twins with childhood-onset narcolepsy with cataplexy, and the parenting effects of hearing loss in one co-twin. Media interest in twins covers a new Broadway musical based on the conjoined twins Violet and Daisy Hilton, male twins becoming famous in fashion, twins who turned 102 and unique insights from a conjoined twin survivor. This article is dedicated to the memory of Elizabeth (Liz) Hamel, DZA twin who met her co-twin for the first time at age seventy-eight years. Liz and her co-twin, Ann Hunt, are listed in the 2015 Guinness Book of Records as the longest separated twins in the world.

  20. Sex Differences in Parietal Lobe Structure and Development

    OpenAIRE

    Salinas, Joel; Mills, Elizabeth D.; Conrad, Amy L.; Koscik, Timothy; Andreasen, Nancy C; Nopoulos, Peg

    2012-01-01

    Structural MRI studies provide evidence for sex differences in the human brain. Differences in surface area and the proportion of gray to white matter volume are observed, particularly in the parietal lobe. To our knowledge, there are no studies examining sex differences of parietal lobe structure in younger populations or in the context of development. The current study evaluated sex difference in the structure of the parietal lobe in children (7-17 years of age). Also, by adding the cohort ...

  1. Neuropsychological profile in patients with temporal lobe epilepsy

    OpenAIRE

    Marques, Daniela; Ferreira, Naide; Horácio, Góis; Reis, Alexandra; Jacinto, Gonçalo

    2013-01-01

    The temporal lobe epilepsy (TLE) is the most common type of refractory epilepsy in adults. There is a wide consensus regarding the commitment of memory in temporal lobe epilepsy with hippocampal sclerosis. However, the consensus is not as widespread with respect to the other functions such as attention, executive functions, language and intellectual performance. For this study we analyzed retrospectively a group of 76 patients with refractory epilepsy, 48 patients with temporal lobe epilepsy ...

  2. Planck revealed bulk motion of Centaurus A lobes

    CERN Document Server

    De Paolis, F; Nucita, A A; Ingrosso, G; Kashin, A L; Khachatryan, H G; Mirzoyan, S; Yegorian, G; Jetzer, Ph; Qadir, A; Vetrugno, D

    2015-01-01

    Planck data towards the active galaxy Centaurus A are analyzed in the 70, 100 and 143 GHz bands. We find a temperature asymmetry of the northern radio lobe with respect to the southern one that clearly extends at least up to 5 degrees from the Cen A center and diminishes towards the outer regions of the lobes. That transparent parameter - the temperature asymmetry - thus has to carry a principal information, i.e. indication on the line-of-sight bulk motion of the lobes, while the increase of that asymmetry at smaller radii reveals the differential dynamics of the lobes as expected at ejections from the center.

  3. ACCESSORY LOBE OF RIGHT LUNG: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    A.K. Manicka Vasuki

    2015-12-01

    Full Text Available Anatomical variations of lungs in the form of Accessory lobe and abnormality in the fissures are important for the surgeons to avoid possible injuries to the neighbouring structures. We report a case of Accessory lobe of right lung between middle and lower lobe in a male cadaver which was found during routine dissection in the Anatomy department, PSG IMS & R. Fissure and lobes of left lung was normal. Anatomical knowledge of such variations are helpful for Cardiothoracic surgeons in lobectomies, surgical resections involving individual segments and for Radiologists for interpreting X – rays,CT & MRI scans.

  4. Is the posterior parietal lobe involved in working memory retrieval? Evidence from patients with bilateral parietal lobe damage.

    Science.gov (United States)

    Berryhill, Marian E; Olson, Ingrid R

    2008-01-01

    Neuroimaging evidence suggests that the parietal lobe has an important role in memory retrieval, yet neuropsychology is largely silent on this topic. Recently, we reported that unilateral parietal lobe damage impairs various forms of visual working memory when tested by old/new recognition. Here, we investigate whether parietal lobe working memory deficits are linked to problems at retrieval. We tested two patients with bilateral parietal lobe damage in a series of visual working memory tasks that probed recall and old/new recognition. Stimuli were presented sequentially and several stimulus categories were tested. The results of these experiments show that parietal lobe damage disproportionately impairs old/new recognition as compared to cued recall across stimulus categories. The observed performance dissociation suggests that the posterior parietal lobe plays a particularly vital role in working memory retrieval.

  5. Modelling the influence of amnionicity on the severity of twin-twin transfusion syndrome in monochorionic twin pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Ross, Michael G [Department of Obstetrics and Gynecology, Harbor University of California-Los Angeles Medical Center, Torrance, CA 90502 (United States); Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)

    2004-03-21

    Clinical treatment for diamniotic-monochorionic twin-twin transfusion syndrome (TTTS) may include conversion of diamniotic pregnancies to a monoamniotic-monochorionic state by disrupting the amnion septum. We sought to test the underlying hypothesis, i.e. that a monoamniotic state reduces the severity of TTTS. With use of our previously developed mathematical model of two equal fetoplacental circulatory units connected by various sizes and types of placental anastomoses, we compared the haemodynamic and amniotic fluid dynamics of monoamniotic and diamniotic twins that develop TTTS. We used three anastomotic patterns that produce severe, moderate or mild forms of TTTS, respectively, in our diamniotic-monochorionic twin model. Monoamnionicity was modelled by adding the two amniotic fluid volumes and using the volume-averaged amniotic fluid osmolality. The results were as follows: for severe TTTS, small differences develop between diamniotic and monoamniotic donor twins in fetal urine production, swallowed volume, blood volume, blood pressures, net fetofetal transfusion, and blood and amniotic fluid osmolality. However, the circulatory imbalance between the monoamniotic twins deteriorates similar to that of diamniotic twins. The pathophysiological differences tend to disappear for milder TTTS. In conclusion, our model suggests that the uncommon finding of TTTS in monoamniotic twins is not due to the presence of a single amniotic sac. Rather, clinically significant differences in anastomotic patterns and the delayed or lack of identification of manifestations in monoamniotic twins account for the reduced rate of TTTS diagnosis. Based on these results we expect the clinical disruption of the amnion septum in diamniotic-monochorionic TTTS pregnancies to have only minimal benefits. (note)

  6. Neonatal morbidity in growth-discordant monochorionic twins: comparison between the larger and the smaller twin.

    Science.gov (United States)

    Lopriore, Enrico; Sluimers, Carolien; Pasman, Suzanne A; Middeldorp, Johanna M; Oepkes, Dick; Walther, Frans J

    2012-08-01

    Fetal growth restriction in singletons has been shown to enhance fetal lung maturation and reduce the risk of respiratory distress syndrome due to increased endogenous steroid production. However, data on lung maturation in growth-discordant monochorionic (thus, identical) twins are lacking. Our objective was to compare the risk of severe neonatal morbidity between the larger and the smaller twin in monochorionic twins with birth weight discordance (BWD). We included in the study all consecutive monochorionic diamniotic pregnancies with severe BWD (≥25%) and two live-born twins delivered at our center (n=47 twin pairs). We compared the incidence of neonatal morbidity, particularly respiratory distress syndrome (RDS), and cerebral lesions between the larger and the smaller co-twin. The incidence of severe neonatal morbidity in the larger and smaller twin was 38% (18/47) and 19% (9/47), respectively (odds ratio (OR) 2.66, 95% confidence interval (CI) 0.94-7.44) and was due primarily to the higher incidence of RDS, 32% (15/47) and 6% (3/47), respectively (OR 6.88, 95% CI 1.66-32.83). In conclusion, this study shows that the larger twin in monochorionic twin pairs with BWD is at increased risk of severe neonatal morbidity, particularly RDS, compared to the smaller twin.

  7. NOTE: Thrombosis of anastomoses may affect the staging sequence of twin twin transfusion syndrome

    Science.gov (United States)

    van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; van Gemert, Martin J. C.

    2008-03-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. Supported in part by the European Community Euro-twin-2-twin project (JPHMvdW) and by the National Institutes of Health, grant HL40899 (MGR).

  8. Acardiac Twinning (Twin Reversed Arterial Perfusion Sequence: A Review of Prenatal Management

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2005-06-01

    Full Text Available Acardiac twinning, or the twin reversed arterial perfusion (TRAP sequence, occurs in 1% of monozygotic twins, or 1 in 35,000 births. It is caused by the development of arterioarterial vascular anastomoses between the umbilical arteries of monozygotic twins early in embryogenesis. The pump twin may be associated with congenital anomalies and chromosomal abnormalities. Therefore, it is recommended that prenatal genetic testing be offered whenever pregnancy is complicated by acardiac twinning. The treatment options for acardiac twinning include observation, medical management, amniodrainage, and invasive treatment such as hysterotomy with selective delivery of the acardiac twin, intrafetal ablation of the acardiac twin by alcohol, laser, thermocoagulation or radiofrequency, fetoscope-guided funicular occlusion by ligation, laser or thermocoagulation, and ultrasound-guided funicular occlusion by ligation, cord compression, thermocoagulation or intrafunicular embolization with foreign bodies. If invasive treatment is indicated, the simplicity, safety, and efficacy of the chosen technique should be considered. An intrafetal approach has been shown to be superior to a funicular occlusion approach. Ultrasound-guided intrafetal laser ablation or radiofrequency ablation is believed to be the treatment of choice based on currently available data. This review emphasizes the necessity to carefully search for any possible associated anomaly in the pump twin by both genetic testing and sonographic examination, and to prudently consider invasive treatment only in pregnancies which would potentially benefit from the prenatal intervention.

  9. Effect of co-twin gender on neurodevelopmental symptoms: a twin register study.

    Science.gov (United States)

    Eriksson, Jonna Maria; Lundström, Sebastian; Lichtenstein, Paul; Bejerot, Susanne; Eriksson, Elias

    2016-01-01

    Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are neurodevelopmental disorders thought to have both genetic and environmental causes. It has been hypothesized that exposure to elevated levels of prenatal testosterone is associated with elevated traits of ASD and ADHD. Assuming that testosterone levels from a dizygotic male twin fetus may lead to enhanced testosterone exposure of its co-twins, we aimed to test the prenatal testosterone hypothesis by comparing same-sex with opposite-sex dizygotic twins with respect to neurodevelopmental symptoms. Neuropsychiatric traits were assessed in a population-based twin cohort from the Child and Adolescent Twin Study in Sweden (CATSS). Parental interviews were conducted for 16,312 dizygotic twins, 9 and 12 years old, with the Autism-Tics, ADHD, and other Comorbidities inventory (A-TAC). Girls with a female co-twin had an increased risk of reaching the cut-off score for ADHD compared with girls with a male co-twin. Both boys and girls with a female co-twin displayed a larger number of traits related to attention deficit and repetitive and stereotyped behaviors than those with a male twin. In girls, this also extended to social interaction and the combined measures for ASD and ADHD, however, with small effect sizes. Our results are reverse to what would have been expected from the prenatal testosterone hypothesis but consistent with a previous study of ASD and ADHD traits in dizygotic twins. The seemingly protective effect for girls of having a twin brother may be an effect of parent report bias, but may also be an unexpected effect of sharing the intrauterine environment with a male co-twin.

  10. Far-Field to Near-Field Coupling for Enhancing Light-Matter Interaction

    Science.gov (United States)

    Bonakdar, Alireza

    This thesis reports on theoretical, modeling, and experimental research within the framework of a key scientific question, which is enhancing the coupling between diffraction-limited far-field and sub-wavelength quantum emitter/absorber. A typical optoelectronic device delivers an optical process such as light detection (e.g. photodetector) or light intensity modulation (e.g. electro-absorptive modulator). In conventional devices, optical process is in the form of far-field or guided wave modes. The main aim of this thesis is to show that converting these modes into near-field domain can enhance the performance of the optoelectronic device. Light in the form of far-field can be converted into near-field domain by the optical antenna. Among different optoelectronic devices, this thesis focuses mainly on integrating the optical antenna with infrared photodetectors. The available semiconductors have weak infrared absorption that reduces light detection efficiency. Integration of the optical antenna with infrared absorber (such as quantum wells in quantum well infrared photodetector (QWIP)) increases the infrared absorption. Particularly this integration is favorable as the optical antenna has low metallic loss in infrared region. The author of this thesis believes that optical antenna has unique properties in confining light on the scale of deep sub-wavelength, enhancing electric field intensity and delivering optical energy to semiconductor absorbers. These properties are reaching into practical applications only if overall optical performance is low loss, parameter free (independent of optical parameters such a polarization and angle of incident) and broadband. In this thesis, the integration of optical antenna with infrared photodetectors and thermophotovoltaic are researched and developed which satisfy the aforementioned criteria. In addition, several different optical antennas have been designed, fabricated and characterized in order to analyze and demonstrate

  11. The effect of chorionicity and twin-to-twin delivery time interval on short-term outcome of the second twin

    DEFF Research Database (Denmark)

    Hjortø, Sofie; Nickelsen, Carsten; Petersen, Janne;

    2013-01-01

    Abstract Objectives: To investigate the effect of chorionicity and twin-to-twin delivery time interval on short-term outcome in the second twin. Additionally, to investigate predictors of adverse outcome in both twins. Methods: Data included vaginally delivered twins (≥ 36 weeks) from Copenhagen...... University Hospitals (2001-09). The association between delivery interval and adverse outcome parameters were compared for monochorionic (MC) and dichorionic (DC) twins by multiple linear regression. Predictors were studied by logistic regression. Results: There were 554 twin pairs: 57 MC and 485 DC. We...... found no difference in the decrease of pH (p = 0.912) and Apgar (p = 0.609) in relation to increasing time interval. Neonatal unit (NICU) admissions did not differ (p = 0.167). Apgar ≤ 7 (p twin, whereas first (p = 0.001) or second (p twin Apgar...

  12. The effect of chorionicity and twin-to-twin delivery time interval on short-term outcome of the second twin.

    Science.gov (United States)

    Hjortø, Sofie; Nickelsen, Carsten; Petersen, Janne; Secher, Niels Jørgen

    2014-01-01

    To investigate the effect of chorionicity and twin-to-twin delivery time interval on short-term outcome in the second twin as well as to investigate the predictors of adverse outcome in both twins. Data included vaginally delivered twins (≥36 weeks) from Copenhagen University Hospitals (2001-2009). The association between delivery interval and adverse outcome parameters was compared for monochorionic (MC) and dichorionic (DC) twins by multiple linear regression. Predictors were studied by logistic regression. There were 554 twin pairs, of which 57 were MC and 485 DC. We found no difference in the decrease of pH (p = 0.912) and Apgar (p = 0.609) in relation to increasing time interval. Neonatal unit (NICU) admissions did not differ (p = 0.167). Apgar ≤7 (p < 0.001) and pH ≤ 7.20 (p = 0.002) increased first twin risk of NICU admission, whereas first (p = 0.001) or second (p < 0.001) twin Apgar ≤7 and second twin pH ≤7.00 (p = 0.003) increased second twin risk of NICU admission. Increasing delivery interval was associated with a significant decrease in pH and Apgar, but there was no difference between MC and DC twins. Low Apgar of the first twin increased the risk of second twin NICU admission.

  13. Rare Complications with Monochorionic Twins: Ultrasonography and Pathology Correlations

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mi Jin [Cheil General Hospital and Women' s Healthcare Center, Kwandong University College of Medicine, Seoul (Korea, Republic of)

    2009-12-15

    We reviewed the sonographic features of rare complications with monochorionic twins and we correlated these features with the pathologic findings. The complications, including the twin reversed arterial perfusion sequence, the twin embolization syndrome, the conjoined twins and umbilical cord entanglement. A better understanding of these complications can aid making an accurate prenatal diagnosis and predicting the fetal outcome

  14. Dislocation Mechanism of Twinning in Ni-Mn-Ga

    Science.gov (United States)

    Zárubová, N.; Ge, Y.; Gemperlová, J.; Gemperle, A.; Hannula, S.-P.

    2012-03-01

    Tensile tests were performed in situ in a transmission electron microscope to investigate the twinning mechanism in non-modulated Ni-Mn-Ga martensite. The reorientation of the twin variants occurs via twinning dislocations. Their generation and movement were followed; the glide plane and Burgers vector were verified. Individual twinning dislocations were visualized.

  15. Mechanical twinning in small quartz crystals

    Science.gov (United States)

    Laughner, J. W.; Newnham, R. E.; Cross, L. E.

    1982-02-01

    Quartz is known to be ferrobielastic; that is, quartz crystals have domain states (Dauphiné twins) which differ in their elastic compliance values and which can be switched by an appropriately oriented stress. Polycrystalline quartz has also been reported (Tullis 1970) to show preferential orientation of these domains following application of large uniaxial stresses. These experiments were designed to study twinning of synthetic quartz “grains” (minimum size 0.07×0.07×0.02 cm) in specially-constructed composites and of grains in three natural quartz aggregates — a quartzite, a novaculite, and a jasper. Backreflection X-ray techniques were used to verify twinning in the composite grains, while special electroding and electrical detection allowed the twinning processes to be examined in “real time.” Small synthetic quartz crystals were found to behave identically to the massive samples previously studied. Electrical pulses due to the reversal of piezoelectric coefficient d 11 in twinned quartz were detected from quartzite and from the man-made composites. Novaculite also gave electrical pulses which were probably from twinning (evidenced by the correlation of expected and observed pulse sizes and shapes), while no pulses from the jaspers indicative of twinning were detected. Grain size distribution differences are considered the main structural reason for the different behaviors.

  16. On the twinning in ZnPd.

    Science.gov (United States)

    Ivarsson, Dennis C A; Burkhardt, Ulrich; Heggen, Marc; Ormeci, Alim; Armbrüster, Marc

    2017-02-22

    The intermetallic compound ZnPd has demonstrated excellent catalytic properties in methanol steam reforming. While it is known that defects and microstructures influence the catalytic properties, little is known about the defects occurring in ZnPd. Due to recent advances in synthetic methods, coarse-grained ZnPd samples are accessible. This enables the detection and investigation of twinning in ZnPd by studying the twinned regions from the macroscopic scale by polarised light and electron backscattering diffraction (EBSD) down to the atomic scale by high-resolution transmission electron microscopy (HR-TEM). Twinning occurs in {101} and is coupled with a change in the c/a ratio in the vicinity of the twin boundary. Quantum chemical calculations result in only very small energy differences between the ideal and the twinned structure, explaining the experimentally observed thermal stability of the latter. The chemical bonding was investigated by the electron localizability indicator (ELI) and compared to the one in the ideal structure. The results confirm twinning along the {101} plane and demonstrate the high stability of the twin boundaries after formation.

  17. Twin and Triplet Drugs in Opioid Research

    Science.gov (United States)

    Fujii, Hideaki

    Twin and triplet drugs are defined as compounds that contain respectively two and three pharmacophore components exerting pharmacological effects in a molecule. The twin drug bearing the same pharmacophores is a "symmetrical twin drug", whereas that possessing different pharmacophores is a "nonsymmetrical twin drug." In general, the symmetrical twin drug is expected to produce more potent and/or selective pharmacological effects, whereas the nonsymmetrical twin drug is anticipated to show both pharmacological activities stemming from the individual pharmacophores (dual action). On the other hand, nonsymmetrical triplet drugs, which have two of the same pharmacophores and one different moiety, are expected to elicit both increased pharmacological action and dual action. The two identical portions could bind the same receptor sites simultaneously while the third portion could bind a different receptor site or enzyme. This review will mainly focus on the twin and triplet drugs with an evaluation of their in vivo pharmacological effects, and will also include a description of their pharmacology and synthesis.

  18. Computational Studies of Lobed Forced Mixer Flows

    Institute of Scientific and Technical Information of China (English)

    H.Hu; S.C.M.Yu; 等

    1998-01-01

    Full Navier-Stokes Analyses have been conducted for the flows behind the trailing edge of a lobed forced mixer,The governing equations are derived from the time-dependent compressible Navier-Stokes equations and discretized in the finite-difference form.A simple two-layer eddy viscosity model has also been used to account for the turbulence.Computed results are compared with some of the velocity measurements using a laser-Doppler anemomter(Yu and Yip (1997),In General,good agreement can be obtained in the streamwise mean velocity distribution but the decay of the streamwise circulation is underpredicted.Some suggestions to the discrepancy are proposed.

  19. Monocarboxylate transporters in temporal lobe epilepsy

    DEFF Research Database (Denmark)

    Lauritzen, Fredrik; Eid, Tore; Bergersen, Linda H

    2013-01-01

    Epilepsy is a serious neurological disorder that affects approximately 1 % of the general population, making it one of the most common disorders of the central nervous system. Furthermore, up to 40 % of all patients with epilepsy cannot control their seizures with current medications. More...... efficacious treatments for medication refractory epilepsy are therefore needed. A better understanding of the mechanisms that cause this disorder is likely to facilitate the discovery of such treatments. Impairment in cerebral energy metabolism has been proposed as a possible causative factor...... in the pathogenesis of temporal lobe epilepsy (TLE), which is one of the most common types of medication-refractory epilepsies in adults. In this review, we will discuss some of the current hypotheses regarding the possible causal relationship between brain energy metabolism and TLE. Emphasis will be placed...

  20. Psychosis in temporal lobe epilepsy: atypical presentation.

    Science.gov (United States)

    Gandhi, Priya; Ogunyemi, Boluwaji; MacDonald, Andrea; Gadit, Amin

    2012-01-18

    A 55-year-old lady was admitted following a concern raised by family members who had noticed a change in behaviour in terms of declining mood, paranoia with expression of belief that she was being bugged, also reported smelling perfume and after shave lotion. She had a prior diagnosis of bipolar mood disorder and was on lithium but remained no-compliant with her prescribed medication in the 10 weeks before admission. Upon admission, necessary investigations were performed including CT scan and EEG. Her CT was normal but EEG was grossly abnormal. Neurology consultation was sought and a sleep deprived EEG and MRI was ordered. Meanwhile, carbamezipine was commenced in view of the change in diagnosis to that of temporal lobe epilepsy. The patient responded very well to this regime and improved in all spheres. She was finally discharged with follow-up appointments with both neurology and psychiatry clinics.

  1. Frontal Lobe Function in Chess Players

    Directory of Open Access Journals (Sweden)

    Vahid Nejati

    2012-05-01

    Full Text Available Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  2. Xenomelia: a new right parietal lobe syndrome.

    Science.gov (United States)

    McGeoch, Paul D; Brang, David; Song, Tao; Lee, Roland R; Huang, Mingxiong; Ramachandran, V S

    2011-12-01

    Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healthy legs (two right, one left and one, at first, bilateral and then left only) were recruited and underwent magnetoencephalography (MEG) scans during tactile stimulation of sites above and below the desired amputation line. Regions of interest (ROIs) in each hemisphere (superior parietal lobule (SPL), inferior parietal lobule, S1, M1, insula, premotor cortex and precuneus) were defined using FreeSurfer software. Analysis of average MEG activity across the 40-140 ms post-stimulation timeframe was carried out using an unpaired t test. This revealed significantly reduced activation only in the right SPL ROI for the subjects' affected legs when compared with both subjects' unaffected legs and that of controls. The right SPL is a cortical area that appears ideally placed to unify disparate sensory inputs to create a coherent sense of having a body. The authors propose that inadequate activation of the right SPL leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image, with a resulting desire for amputation. The authors introduce the term 'xenomelia' as a more appropriate name than apotemnophilia or body integrity identity disorder, for what appears to be an unrecognised right parietal lobe syndrome.

  3. Teaching about twins: college courses and public lectures.

    Science.gov (United States)

    Segal, Nancy L

    2013-12-01

    The present article describes teaching experiences and observations in college courses and public lectures on twins. It is concluded that much more information about twins, at both research and practical levels, requires general dissemination. This discussion is followed by reviews of recent twin research on the topics of obesity control, post-zygotic mutation, in vitro fertilization, and schisis-associated defects. Media reports of twins accused of rape, infant Chinese twins sold separately for profit, a twin CEO, and twins pursuing the same career are presented.

  4. Acardiac Parabiotic Fetus: A Rare Complication of Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Sood S

    2015-10-01

    Full Text Available Acardiac parabiotic fetus is sequelae of complication of monochorionic monoamniotic twin pregnancy also known as Twin Reversed Arterial Perfusion Sequence (TRAP. It is rare affecting 1 in 35,000 births and 1 % of monozygotic twins. Acardiac parabiotic twin commonly known as parasite occurs rarely and may lead to high output cardiac failure, hydrops or premature delivery in the pump fetus. In this report, we present a 23 years old primigravida with twin pregnancy, with twin reversed arterial perfusion sequence with one of the twins being acardiac anceps and the other normal pump fetus. This association is relatively uncommon and therefore rarely documented.

  5. Familial aggregation of atrial fibrillation: a study in Danish twins

    DEFF Research Database (Denmark)

    Christophersen, Ingrid Elisabeth; Ravn, Lasse Steen; Budtz-Joergensen, Esben

    2009-01-01

    BACKGROUND: Heritability may play a role in nonfamilial atrial fibrillation (AF). We hypothesized that a monozygotic (MZ) twin whose co-twin was diagnosed with AF would have an increased risk of the disease compared with a dizygotic (DZ) twin in the same situation. METHODS AND RESULTS: A sample...... of 1137 same-sex twin pairs (356 MZ and 781 DZ pairs) in which one or both members were diagnosed with AF were identified in The Danish Twin Registry. Concordance rates were twice as high for MZ pairs than for DZ pairs regardless of sex (22.0% versus 11.6%, P...-free survival times, we compared the time span between occurrences of disease in MZ and DZ twins. The unaffected twin was included when his or her twin-sibling (the index twin) was diagnosed with AF. After adjustment for age at entry, MZ twins had a significantly shorter event-free survival time (hazard ratio...

  6. Unequal but monozygous: a history of twin-twin transfusion syndrome.

    Science.gov (United States)

    Obladen, Michael

    2010-03-01

    Twin-twin transfusion is the major cause of mortality and morbidity in monochorionic twins. Its pathogenesis has been gradually elucidated over the last three centuries. Among obstetricians, there was a long-lasting controversy on the existence of placental anastomoses and whether or not to tie the placental end of the firstborn infant's cord. However, a twin pregnancy practically never could be excluded. Stalpart van der Wiel described a twin-twin vessel connection in 1687. Studies on interfetal anastomoses using injection of placental vessels were published by Smellie in 1752, Osiander in 1781, and Brachet in 1821. Different types of anastomoses, and their associated fetal disorders were classified by Schatz in a series of papers at the end of the 19(th) century. With the advent of ultrasound and laser techniques, prenatal diagnosis and treatment became available in the last decade of the 20(th) century.

  7. The Vanishing Twin Syndrome: Two Cases of Extreme Malformations Associated With Vanished Twins.

    Science.gov (United States)

    Shinnick, Julia K; Khoshnam, Nasim; Archer, Sydney R; Quigley, Philip C; Robinson, Haynes; Keene, Sarah; Santore, Matthew T; Hill, Sarah; Patel, Binita; Shehata, Bahig M

    2017-01-01

    Two cases of devastating fetal malformations associated with vanished monochorionic twins were identified upon review of pathology files. A 35-year-old G1P0 woman and 36-year-old G3P1 woman were both diagnosed with an intrauterine twin gestation via transvaginal ultrasound at 10 weeks. The spectrum of fetal anomalies ranged from omphalocele, bilateral upper extremity, and unilateral lower extremity hypoplasia, to craniofacial malformation with diaphragmatic hernia. On histopathologic examination, the placentas demonstrated vascular anastomoses between the surviving co-twin and the "vanished" fetal sac. We propose anastomotic placental vasculature as a contributing factor to the observed fetal malformations. Additionally, genetic or teratogenic factors may have been attributed to the demise of the first twin and the anomalies seen in the other twin. While such instances are rare, they are important to consider when counseling patients regarding outcomes associated with a monochorionic vanished twin.

  8. Twin trisomies-Edward and Patau syndromes.

    Science.gov (United States)

    Massiah, Nadine; Griffiths, Emma; Bamigboye, Vincent

    2008-11-01

    To report the rare occurrence of dichorionic diamniotic twins with dissimilar aneuploidies. Case report. District general hospital. A 36-year-old woman conceived by in vitro fertilization. Dichorionic diamniotic twins were found to have elevated nuchal translucencies and cystic hygromas. Intrauterine deaths occurred at 13 and 17 weeks gestation. Medical termination of pregnancy. Karyotypes. Cytogenetic studies confirmed Edward's and Patau's syndromes. The aetiology is unknown but maternal age and in vitro fertilization may be linked since the incidence of aneuploidy rises with maternal age and the incidence of twins' increases with assisted reproductive techniques. This case highlights the need for obstetricians to have good communication and counselling skills.

  9. Undiagnosed xiphopagus twins: a perinatal malady

    Directory of Open Access Journals (Sweden)

    Gowri Dorairajan

    2012-02-01

    Full Text Available Conjoined twins are a very rare entity. It is associated with poor survival rate in the presence of vital organ sharing. The entity can be diagnosed as early as the first trimester. A conjoined twin diagnosed late in labor is a malady with high perinatal mortality and maternal morbidity. We present one such case of xiphopagus twins. The management of a case diagnosed late in labor can be very challenging. Such obstetric challenges can be avoided by a meticulous early scan with a high index of suspicion, especially in the absence of separating membrane while scanning multiple pregnancies.

  10. New growth mode through decorated twin boundaries.

    Science.gov (United States)

    Bleikamp, Sebastian; Thoma, Arne; Polop, Celia; Pirug, Gerhard; Linke, Udo; Michely, Thomas

    2006-03-24

    Scanning tunneling microscopy and low energy electron diffraction were used to investigate the growth of partly twinned Ir thin films on Ir(111). A transition from the expected layer-by-layer to a defect dominated growth mode with a fixed lateral length scale and increasing roughness is observed. During growth, the majority of the film is stably transformed to twinned stacking. This transition is initiated by the energetic avoidance of the formation of intrinsic stacking faults compared to two independent twin faults. The atomistic details of the defect kinetics are outlined.

  11. Intravenous nutrition during a twin pregnancy.

    Science.gov (United States)

    Karamatsu, J T; Boyd, A T; Cooke, J; Vinall, P S; McMahon, M J

    1987-01-01

    A case is reported of a woman in the third trimester of a twin pregnancy who required intravenous nutrition because of inadequate absorption of nutrients due to a jejunoileal bypass. Weight gain was poor, and there was evidence of intrauterine growth retardation before commencement of intravenous feeding. She received overnight intravenous nutrition for 6 weeks and gained weight with ultrasound evidence of fetal growth. During the 33rd week of gestation, she was delivered of healthy twin males who were at appropriate birth weights and development for their age of gestation. The considerations in intravenous nutrition for a twin pregnancy after jejunoileal bypass are discussed.

  12. Nanoscale growth twins in sputtered metal films

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Amit [Los Alamos National Laboratory; Anderoglu, Osman [Los Alamos National Laboratory; Hoagland, Richard G [Los Alamos National Laboratory; Zhang, X [TEXAS A& M

    2008-01-01

    We review recent studies on the mechanical properties of sputtered Cu and 330 stainless steel films with {l_brace}1 1 1{r_brace} nanoscale growth twins preferentially oriented perpendicular to growth direction. The mechanisms of formation of growth twins during sputtering and the deformation mechanisms that enable usually high strengths in nanotwinned structures are highlighted. Growth twins in sputtered films possess good thermal stability at elevated temperature, providing an approach to extend the application of high strength nanostructured metals to higher temperatures.

  13. TwinFocus CPV system

    Science.gov (United States)

    Nardello, Marco; Centro, Sandro

    2017-09-01

    TwinFocus® is a CPV solution that adopts quasi-parabolic, off axis mirrors, to obtain a concentration of 760× on 3J solar cells (Azur space technology) with 44% efficiency. The adoption of this optical solution allows for a cheap, lightweight and space efficient system. In particular, the addition of a secondary optics to the mirror, grants an efficient use of space, with very low thicknesses and a compact modular design. Materials are recyclable and allow for reduction of weights to a minimum level. The product is realized through the cooperation of leading edge industries active in automotive lighting and plastic materials molding. The produced prototypes provide up to 27.6% efficiency according to tests operated on the field with non-optimal spectral conditions.

  14. Rotating superconductor magnet for producing rotating lobed magnetic field lines

    Science.gov (United States)

    Hilal, Sadek K.; Sampson, William B.; Leonard, Edward F.

    1978-01-01

    This invention provides a rotating superconductor magnet for producing a rotating lobed magnetic field, comprising a cryostat; a superconducting magnet in the cryostat having a collar for producing a lobed magnetic field having oppositely directed adjacent field lines; rotatable support means for selectively rotating the superconductor magnet; and means for energizing the superconductor magnet.

  15. Lung lobe segmentation based on statistical atlas and graph cuts

    Science.gov (United States)

    Nimura, Yukitaka; Kitasaka, Takayuki; Honma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Mori, Kensaku

    2012-03-01

    This paper presents a novel method that can extract lung lobes by utilizing probability atlas and multilabel graph cuts. Information about pulmonary structures plays very important role for decision of the treatment strategy and surgical planning. The human lungs are divided into five anatomical regions, the lung lobes. Precise segmentation and recognition of lung lobes are indispensable tasks in computer aided diagnosis systems and computer aided surgery systems. A lot of methods for lung lobe segmentation are proposed. However, these methods only target the normal cases. Therefore, these methods cannot extract the lung lobes in abnormal cases, such as COPD cases. To extract lung lobes in abnormal cases, this paper propose a lung lobe segmentation method based on probability atlas of lobe location and multilabel graph cuts. The process consists of three components; normalization based on the patient's physique, probability atlas generation, and segmentation based on graph cuts. We apply this method to six cases of chest CT images including COPD cases. Jaccard index was 79.1%.

  16. Cohort Profile : The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry)

    NARCIS (Netherlands)

    Gatz, Margaret; Harris, Jennifer R.; Kaprio, Jaakko; McGue, Matt; Smith, Nicholas L.; Snieder, Harold; Spiro, Avron; Butler, David A.

    2015-01-01

    The National Academy of Sciences-National Research Council Twin Registry (NAS-NRC Twin Registry) is a comprehensive registry of White male twin pairs born in the USA between 1917 and 1927, both of the twins having served in the military. The purpose was medical research and ultimately improved clini

  17. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.

    2008-01-01

    In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...... pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine...

  18. Parasitic twin with gastroschisis is one of the rarest variant of conjoined twins: a case report.

    Science.gov (United States)

    Baskaran, D; Aleem, M A; Ravi, R

    2015-04-01

    We report a case of parasitic twin or incomplete or heteropagus twining of extra portions of a pelvis, lower and upper limbs, duplication of genitalia and herniation of intestinal tract with spleen-variant of conjoined twinning (CT) consistent with fusion of two embryos followed by resorption of the caudal half of one of them, resulting in a normal male baby with the upper half of a male parasitic twin fused to his chest.

  19. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.

    2008-01-01

    pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine......In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...

  20. Tsunami Size Distributions at Far-Field Locations from Aggregated Earthquake Sources

    Science.gov (United States)

    Geist, E. L.; Parsons, T.

    2015-12-01

    The distribution of tsunami amplitudes at far-field tide gauge stations is explained by aggregating the probability of tsunamis derived from individual subduction zones and scaled by their seismic moment. The observed tsunami amplitude distributions of both continental (e.g., San Francisco) and island (e.g., Hilo) stations distant from subduction zones are examined. Although the observed probability distributions nominally follow a Pareto (power-law) distribution, there are significant deviations. Some stations exhibit varying degrees of tapering of the distribution at high amplitudes and, in the case of the Hilo station, there is a prominent break in slope on log-log probability plots. There are also differences in the slopes of the observed distributions among stations that can be significant. To explain these differences we first estimate seismic moment distributions of observed earthquakes for major subduction zones. Second, regression models are developed that relate the tsunami amplitude at a station to seismic moment at a subduction zone, correcting for epicentral distance. The seismic moment distribution is then transformed to a site-specific tsunami amplitude distribution using the regression model. Finally, a mixture distribution is developed, aggregating the transformed tsunami distributions from all relevant subduction zones. This mixture distribution is compared to the observed distribution to assess the performance of the method described above. This method allows us to estimate the largest tsunami that can be expected in a given time period at a station.

  1. Probabilistic tsunami hazard assessment at Seaside, Oregon, for near- and far-field seismic sources

    Science.gov (United States)

    GonzáLez, F. I.; Geist, E. L.; Jaffe, B.; KâNoǧLu, U.; Mofjeld, H.; Synolakis, C. E.; Titov, V. V.; Arcas, D.; Bellomo, D.; Carlton, D.; Horning, T.; Johnson, J.; Newman, J.; Parsons, T.; Peters, R.; Peterson, C.; Priest, G.; Venturato, A.; Weber, J.; Wong, F.; Yalciner, A.

    2009-11-01

    The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amplitudes with 1% and 0.2% annual probability of exceedance. The 100-year tsunami is generated most frequently by far-field sources in the Alaska-Aleutian Subduction Zone and is characterized by maximum amplitudes that do not exceed 4 m, with an inland extent of less than 500 m. In contrast, the 500-year tsunami is dominated by local sources in the Cascadia Subduction Zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km. The primary sources of uncertainty in these results include those associated with interevent time estimates, modeling of background sea level, and accounting for temporal changes in bathymetry and topography. Nonetheless, PTHA represents an important contribution to tsunami hazard assessment techniques; viewed in the broader context of risk analysis, PTHA provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard, which can then be combined with vulnerability and exposure to yield estimates of tsunami risk.

  2. Characterization of far-field jet flows from complex nozzles via Particle Tracking Velocimetry

    Science.gov (United States)

    Kim, Jin-Tae; Liberzon, Alex; Zuniga Zamalloa, Carlo; Chamorro, Leonardo P.

    2014-11-01

    Understanding the advection, diffusion and mixing of turbulence and scalars of jet flows under various geometric configurations and Reynolds numbers is of high relevance in environmental and engineering applications. In this experimental study, we characterize the far-field turbulence of jet flows in the proximity of twelve rotor diameters downstream of a series of complex nozzle geometries. The jet flows are released into a still body of water from a series of nozzles of different cross sections but with common hydraulic diameter dh = 0.01 m at a Reynolds number Re = U0*dh/ ν approx. 7000, where U0 is the flow velocity at the outlet of the jet and ν is the kinematic viscosity of the flow. The system is closed-loop and seeded with particles of 100 μm diameter. Results are analyzed from Lagrangian and Eulerian frames of references via 3D particle tracking velocimetry (OpenPTV, www.openptv.net). Lagrangian features of the particles are characterized in terms of the nozzle geometries and high-order turbulence statistics are obtained at various planes within the interrogation volume, which mimics 3D PIV.

  3. Far-Field Voice Activity Detection and Its Applications in Adverse Acoustic Environments

    DEFF Research Database (Denmark)

    Petsatodis, Theodoros

    2012-01-01

    Voice Activity Detection (VAD), being in the focus of speech processing research for many years, is nowadays a mature technology with application in several sectors. Embedded VAD components in telecommunications systems (like in cellular telephony) attempt to reduce power consumption of transmitt......Voice Activity Detection (VAD), being in the focus of speech processing research for many years, is nowadays a mature technology with application in several sectors. Embedded VAD components in telecommunications systems (like in cellular telephony) attempt to reduce power consumption...... of transmitters and bandwidth utilization. VAD technology is also integrated in speech-processing systems, such as Speaker Identification, Automatic Event Detection, and Automatic Speech Recognition, to prevent their operation in the absence of speech, and thus reduce the error rates of each of these systems....... The performance of VAD systems depends strongly on various factors, including the discriminative ability of the classification criterion employed, the dynamics of the additive noise and the signal to noise ratio. Speech signals transmitted within reverberant enclosures and captured using far-field microphones...

  4. Far-field Fano resonance in nanoring lattices modeled from extracted, point dipole polarizability

    Energy Technology Data Exchange (ETDEWEB)

    DeJarnette, Drew; Forcherio, Gregory T. [Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Blake, Phillip [Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Keith Roper, D., E-mail: dkroper@uark.edu [Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

    2014-01-14

    Coupling and extinction of light among particles representable as point dipoles can be characterized using the coupled dipole approximation (CDA). The analytic form for dipole polarizability of spheroidal particles supports rapid electrodynamic analysis of nanoparticle lattices using CDA. However, computational expense increases for complex shapes with non-analytical polarizabilities which require discrete dipole (DDA) or higher order approximations. This work shows fast CDA analysis of assembled nanorings is possible using a single dipole nanoring polarizability extrapolated from a DDA calculation by summing contributions from individual polarizable volume elements. Plasmon resonance wavelengths of nanorings obtained using extracted polarizabilities blueshift as wall dimensions-to-inner radius aspect ratio increases, consistent with published theory and experiment. Calculated far-field Fano resonance energy maximum and minimum wavelengths were within 1% of full volume element results. Considering polarizability allows a more complete physical picture of predicting plasmon resonance location than metal dielectric alone. This method reduces time required for calculation of diffractive coupling more than 40 000-fold in ordered nanoring systems for 400–1400 nm incident wavelengths. Extension of this technique beyond nanorings is possible for more complex shapes that exhibit dipolar or quadrupole radiation patterns.

  5. Reconstruction of far-field tsunami amplitude distributions from earthquake sources

    Science.gov (United States)

    Geist, Eric L.; Parsons, Thomas E.

    2016-01-01

    The probability distribution of far-field tsunami amplitudes is explained in relation to the distribution of seismic moment at subduction zones. Tsunami amplitude distributions at tide gauge stations follow a similar functional form, well described by a tapered Pareto distribution that is parameterized by a power-law exponent and a corner amplitude. Distribution parameters are first established for eight tide gauge stations in the Pacific, using maximum likelihood estimation. A procedure is then developed to reconstruct the tsunami amplitude distribution that consists of four steps: (1) define the distribution of seismic moment at subduction zones; (2) establish a source-station scaling relation from regression analysis; (3) transform the seismic moment distribution to a tsunami amplitude distribution for each subduction zone; and (4) mix the transformed distribution for all subduction zones to an aggregate tsunami amplitude distribution specific to the tide gauge station. The tsunami amplitude distribution is adequately reconstructed for four tide gauge stations using globally constant seismic moment distribution parameters established in previous studies. In comparisons to empirical tsunami amplitude distributions from maximum likelihood estimation, the reconstructed distributions consistently exhibit higher corner amplitude values, implying that in most cases, the empirical catalogs are too short to include the largest amplitudes. Because the reconstructed distribution is based on a catalog of earthquakes that is much larger than the tsunami catalog, it is less susceptible to the effects of record-breaking events and more indicative of the actual distribution of tsunami amplitudes.

  6. Far-field method for the characterisation of three-dimensional fields: vectorial polarimetry

    Directory of Open Access Journals (Sweden)

    Dainty C.

    2010-06-01

    Full Text Available The first attempt to completely characterise a three-dimensional field was done by Ellis and Dogariu with excellent results reported [1] . However, their method is based on near-field techniques, which limits its range of applications. In this work, we present an alternative far-field method for the characterisation of the three-dimensional field that results from the interaction of a tightly focused three-dimensional field [2] with a sub-resolution specimen. Our method is based on the analysis of the scattering-angle-resolved polarisation state distribution across the exit pupil of a high numerical aperture (NA collector lens using standard polarimetry techniques. Details of the method, the experimental setup built to verify its capabilities, and numerical and first experimental evidence demonstrating that the method allows for high sensitivit y on sub-resolution displacements of a sub-resolution specimen shall be presented [3]. This work is funded by Science Foundation Ireland grant No. 07/IN.1/I906 and Shimadzu Corporation, Japan. Oscar Rodríguez is grateful to the National Council for Science and Technology (CONACYT, Mexico for the Ph D scholarship 177627.

  7. Reconstruction of Far-Field Tsunami Amplitude Distributions from Earthquake Sources

    Science.gov (United States)

    Geist, Eric L.; Parsons, Tom

    2016-04-01

    The probability distribution of far-field tsunami amplitudes is explained in relation to the distribution of seismic moment at subduction zones. Tsunami amplitude distributions at tide gauge stations follow a similar functional form, well described by a tapered Pareto distribution that is parameterized by a power-law exponent and a corner amplitude. Distribution parameters are first established for eight tide gauge stations in the Pacific, using maximum likelihood estimation. A procedure is then developed to reconstruct the tsunami amplitude distribution that consists of four steps: (1) define the distribution of seismic moment at subduction zones; (2) establish a source-station scaling relation from regression analysis; (3) transform the seismic moment distribution to a tsunami amplitude distribution for each subduction zone; and (4) mix the transformed distribution for all subduction zones to an aggregate tsunami amplitude distribution specific to the tide gauge station. The tsunami amplitude distribution is adequately reconstructed for four tide gauge stations using globally constant seismic moment distribution parameters established in previous studies. In comparisons to empirical tsunami amplitude distributions from maximum likelihood estimation, the reconstructed distributions consistently exhibit higher corner amplitude values, implying that in most cases, the empirical catalogs are too short to include the largest amplitudes. Because the reconstructed distribution is based on a catalog of earthquakes that is much larger than the tsunami catalog, it is less susceptible to the effects of record-breaking events and more indicative of the actual distribution of tsunami amplitudes.

  8. Paleogene volcanism in Central Afghanistan: Possible far-field effect of the India-Eurasia collision

    Science.gov (United States)

    Motuza, Gediminas; Šliaupa, Saulius

    2017-10-01

    A volcanic-sedimentary succession of Paleogene age is exposed in isolated patches at the southern margin of the Tajik block in the Ghor province of Central Afghanistan. The volcanic rocks range from basalts and andesites to dacites, including adakites. They are intercalated with sedimentary rocks deposited in shallow marine environments, dated biostratigraphically as Paleocene-Eocene. This age corresponds to the age of the Asyābēd andesites located in the western Ghor province estimated by the 40Ar/39Ar method as 54 Ma. The magmatism post-dates the Cimmerian collision between the Tajik block (including the Band-e-Bayan block) and the Farah Rod block located to the south. While the investigated volcanic rocks apparently bear geochemical signatures typical to an active continental margin environment, it is presumed that the magmatism was related to rifting processes most likely initiated by far-field tectonics caused by the terminal collision of the Indian plate with Eurasia (Najman et al., 2017). This event led to the dextral movement of the Farah Rod block, particularly along Hari Rod (Herat) fault system, resulting in the development of a transtensional regime in the proximal southern margin of the Tajik block and giving rise to a rift basin where marine sediments were interbedded with pillow lavas intruded by sheeted dyke series.

  9. EM modeling of far-field radiation patterns for antennas on the GMA-TT UAV

    Science.gov (United States)

    Mackenzie, Anne I.

    2015-05-01

    To optimize communication with the Generic Modular Aircraft T-Tail (GMA-TT) unmanned aerial vehicle (UAV), electromagnetic (EM) simulations have been performed to predict the performance of two antenna types on the aircraft. Simulated far-field radiation patterns tell the amount of power radiated by the antennas and the aircraft together, taking into account blockage by the aircraft as well as radiation by conducting and dielectric portions of the aircraft. With a knowledge of the polarization and distance of the two communicating antennas, e.g. one on the UAV and one on the ground, and the transmitted signal strength, a calculation may be performed to find the strength of the signal travelling from one antenna to the other and to check that the transmitted signal meets the receiver system requirements for the designated range. In order to do this, the antenna frequency and polarization must be known for each antenna, in addition to its design and location. The permittivity, permeability, and geometry of the UAV components must also be known. The full-wave method of moments solution produces the appropriate dBi radiation pattern in which the received signal strength is calculated relative to that of an isotropic radiator.

  10. EM Modeling of Far-Field Radiation Patterns for Antennas on the GMA-TT UAV

    Science.gov (United States)

    Mackenzie, Anne I.

    2015-01-01

    To optimize communication with the Generic Modular Aircraft T-Tail (GMA-TT) unmanned aerial vehicle (UAV), electromagnetic (EM) simulations have been performed to predict the performance of two antenna types on the aircraft. Simulated far-field radiation patterns tell the amount of power radiated by the antennas and the aircraft together, taking into account blockage by the aircraft as well as radiation by conducting and dielectric portions of the aircraft. With a knowledge of the polarization and distance of the two communicating antennas, e.g. one on the UAV and one on the ground, and the transmitted signal strength, a calculation may be performed to find the strength of the signal travelling from one antenna to the other and to check that the transmitted signal meets the receiver system requirements for the designated range. In order to do this, the antenna frequency and polarization must be known for each antenna, in addition to its design and location. The permittivity, permeability, and geometry of the UAV components must also be known. The full-wave method of moments solution produces the appropriate dBi radiation pattern in which the received signal strength is calculated relative to that of an isotropic radiator.

  11. Mode separation in frequency-wavenumber domain through compressed sensing of far-field Lamb waves

    Science.gov (United States)

    Gao, Fei; Zeng, Liang; Lin, Jing; Luo, Zhi

    2017-07-01

    This method based on Lamb waves shows great potential for long-range damage detection. Mode superposition resulting from multi-modal and dispersive characteristics makes signal interpretation and damage feature extraction difficult. Mode separation in the frequency-wavenumber (f-k) domain using a 1D sparse sensing array is a promising solution. However, due to the lack of prior knowledge about damage location, this method based on 1D linear measurement, for the mode extraction of arbitrary reflections caused by defects that are not in line with the sensor array, is restricted. In this paper, an improved compressed sensing method under the far-field assumption is established, which is beneficial to the reconstruction of reflections in the f-k domain. Hence, multiple components consisting of structure and damage features could be recovered via a limited number of measurements. Subsequently, a mode sweeping process based on theoretical dispersion curves has been designed for mode characterization and direction of arrival estimation. Moreover, 2D f-k filtering and inverse transforms are applied to the reconstructed f-k distribution in order to extract the purified mode of interest. As a result, overlapping waveforms can be separated and the direction of defects can be estimated. A uniform linear sensor array consisting of 16 laser excitations is finally employed for experimental investigations and the results demonstrate the efficiency of the proposed method.

  12. ESTIMATION OF FAR-FIELD TSUNAMI POTENTIAL FOR THE CARIBBEAN COAST BASED ON NUMERICAL SIMULATION

    Directory of Open Access Journals (Sweden)

    Narcisse Zaibo

    2003-01-01

    Full Text Available The tsunami problem for the coast of the Caribbean basin is discussed. Briefly the historical data of tsunami in the Caribbean Sea are presented. Numerical simulation of potential tsunamis in the Caribbean Sea is performed in the framework of the nonlinear-shallow theory. The tsunami wave height distribution along the Caribbean Coast is computed. These results are used to estimate the far-field tsunami potential of various coastal locations in the Caribbean Sea. In fact, five zones with tsunami low risk are selected basing on prognostic computations, they are: the bay “Golfo de Batabano” and the coast of province “Ciego de Avila” in Cuba, the Nicaraguan Coast (between Bluefields and Puerto Cabezas, the border between Mexico and Belize, the bay “Golfo de Venezuela” in Venezuela. The analysis of historical data confirms that there was no tsunami in the selected zones. Also, the wave attenuation in the Caribbean Sea is investigated; in fact, wave amplitude decreases in an order if the tsunami source is located on the distance up to 1000 km from the coastal location. Both factors wave attenuation and wave height distribution should be taken into account in the planned warning system for the Caribbean Sea.

  13. Probabilistic tsunami hazard assessment at Seaside, Oregon, for near-and far-field seismic sources

    Science.gov (United States)

    Gonzalez, F.I.; Geist, E.L.; Jaffe, B.; Kanoglu, U.; Mofjeld, H.; Synolakis, C.E.; Titov, V.V.; Areas, D.; Bellomo, D.; Carlton, D.; Horning, T.; Johnson, J.; Newman, J.; Parsons, T.; Peters, R.; Peterson, C.; Priest, G.; Venturato, A.; Weber, J.; Wong, F.; Yalciner, A.

    2009-01-01

    The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amplitudes with 1% and 0.2% annual probability of exceedance. The 100-year tsunami is generated most frequently by far-field sources in the Alaska-Aleutian Subduction Zone and is characterized by maximum amplitudes that do not exceed 4 m, with an inland extent of less than 500 m. In contrast, the 500-year tsunami is dominated by local sources in the Cascadia Subduction Zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km. The primary sources of uncertainty in these results include those associated with interevent time estimates, modeling of background sea level, and accounting for temporal changes in bathymetry and topography. Nonetheless, PTHA represents an important contribution to tsunami hazard assessment techniques; viewed in the broader context of risk analysis, PTHA provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard, which can then be combined with vulnerability and exposure to yield estimates of tsunami risk. Copyright 2009 by the American Geophysical Union.

  14. Reconstruction of Far-Field Tsunami Amplitude Distributions from Earthquake Sources

    Science.gov (United States)

    Geist, Eric L.; Parsons, Tom

    2016-12-01

    The probability distribution of far-field tsunami amplitudes is explained in relation to the distribution of seismic moment at subduction zones. Tsunami amplitude distributions at tide gauge stations follow a similar functional form, well described by a tapered Pareto distribution that is parameterized by a power-law exponent and a corner amplitude. Distribution parameters are first established for eight tide gauge stations in the Pacific, using maximum likelihood estimation. A procedure is then developed to reconstruct the tsunami amplitude distribution that consists of four steps: (1) define the distribution of seismic moment at subduction zones; (2) establish a source-station scaling relation from regression analysis; (3) transform the seismic moment distribution to a tsunami amplitude distribution for each subduction zone; and (4) mix the transformed distribution for all subduction zones to an aggregate tsunami amplitude distribution specific to the tide gauge station. The tsunami amplitude distribution is adequately reconstructed for four tide gauge stations using globally constant seismic moment distribution parameters established in previous studies. In comparisons to empirical tsunami amplitude distributions from maximum likelihood estimation, the reconstructed distributions consistently exhibit higher corner amplitude values, implying that in most cases, the empirical catalogs are too short to include the largest amplitudes. Because the reconstructed distribution is based on a catalog of earthquakes that is much larger than the tsunami catalog, it is less susceptible to the effects of record-breaking events and more indicative of the actual distribution of tsunami amplitudes.

  15. Far-field method for the characterisation of three-dimensional fields: vectorial polarimetry

    Science.gov (United States)

    Rodríguez, O.; Lara, D.; Dainty, C.

    2010-06-01

    The first attempt to completely characterise a three-dimensional field was done by Ellis and Dogariu with excellent results reported [1] . However, their method is based on near-field techniques, which limits its range of applications. In this work, we present an alternative far-field method for the characterisation of the three-dimensional field that results from the interaction of a tightly focused three-dimensional field [2] with a sub-resolution specimen. Our method is based on the analysis of the scattering-angle-resolved polarisation state distribution across the exit pupil of a high numerical aperture (NA) collector lens using standard polarimetry techniques. Details of the method, the experimental setup built to verify its capabilities, and numerical and first experimental evidence demonstrating that the method allows for high sensitivit y on sub-resolution displacements of a sub-resolution specimen shall be presented [3]. This work is funded by Science Foundation Ireland grant No. 07/IN.1/I906 and Shimadzu Corporation, Japan. Oscar Rodríguez is grateful to the National Council for Science and Technology (CONACYT, Mexico) for the Ph D scholarship 177627.

  16. Full characterization of a high-power semiconductor disk laser beam with simultaneous capture of optimally sized focus and farfield.

    Science.gov (United States)

    Borgentun, Carl; Bengtsson, Jörgen; Larsson, Anders

    2011-04-20

    We report on a beam characterization method that is based on the simultaneous measurement of the focus field and the farfield, thus avoiding problems with beam fluctuations during the measurement. By using reflections from both sides of a planoconvex lens, the method implements two branches of an optical system working simultaneously. Also, by letting the planoconvex lens be antireflection treated, and by allowing for both of the reflected fields to fill large and approximately equal areas on a camera detector array, the method significantly lowers the intensity onto the detector array, thus minimizing the need for additional disturbing attenuation filters to avoid camera saturation. In the numerical retrieval of the phase distribution, based on the measured intensity distributions of the focus and farfield, iterative propagation between the two branches is performed. The phase retrieval uses the two-step algorithm for the numerical field propagation conveniently providing an arbitrary choice of sampling distance in each plane.

  17. Computation of Far-Field Noise from Vortex Shedding Behind a Circular Cylinder at Low Reynolds Numbers

    Science.gov (United States)

    Choi, H.; You, D.; Choi, M.-R.; Kang, S.-H.

    1996-11-01

    Laminar vortex sheddings behind a circular cylinder with and without splitter plates attached to the cylinder at low Reynolds numbers are simulated by solving the unsteady incompressible Navier-Stokes equations. The Strouhal number, lift and drag rapidly change with the length of the splitter plate. Far-field noise from the vortex shedding behind the cylinder is computed using the Curle's formulation of the Lighthill acoustic analogy. The acoustic source functions are obtained from the computed near-field velocity and pressure. Numerical results show that the volume quadrupole noise is small at a low Mach number, compared to the surface dipole noise from the cylinder. Variations of the far-field noise characteristics with respect to the splitter plate are being investigated and will be shown in the final presentation. ^* Supported by KOSEF under Contract No. 961-1009-075-2

  18. Far-field super-resolution imaging with a planar hyperbolic metamaterial lens beyond the Fabry-Perot resonance condition

    CERN Document Server

    Lv, Cheng; Jiang, Xunya; Cao, Juncheng

    2014-01-01

    We demonstrate achieving the far-field super-resolution imaging can be realized by using a planar hyperbolic metamaterial lens (PHML), beyond the Fabry-Perot resonance condition. Although the thickness of the PHML is much larger than wavelength, the PHML not only can transmit radiative waves and evanescent waves with high transmission, but also can collect all the waves in the image region with the amplitudes of them being the same order of magnitude. We present a design for a PHML to realize the far-field super-resolution imaging, with the distance between the sources and the images 10 times larger than wavelength. We show the superresolution of our PHML is robust against losses, and the PHML can be fabricated by periodic stacking of metal and dielectric layers.

  19. Emergence of spatiotemporal chaos arising from far-field breakup of spiral waves in the plankton ecological systems

    Institute of Scientific and Technical Information of China (English)

    Liu Quan-Xing; Sun Gui-Quan; Jin Zhen; Li Bai-Lian

    2009-01-01

    It has been reported that the minimal spatially extended phytoplankton-zooplankton system exhibits both tem-poral regular/chaotic behaviour, and spatiotemporal chaos in a patchy environment. As a further investigation by means of computer simulations and theoretical analysis, in this paper we observe that the spiral waves may exist and the spatiotcmporal chaos emerge when the parameters are within the mixed Turing Hopf bifurcation region, which arises from the far-field breakup of the spiral waves over a large range of diffusion coefficients of phytoplankton and zooplankton. Moreover, the spatiotemporal chaos arising from the far-field breakup of spiral waves does not gradually invade the whole space of that region. Our results arc confirmed by nonlinear bifurcation of wave trains. We also discuss ecological implications of these spatially structured patterns.

  20. An Efficient Approach for Identifying Stable Lobes with Discretization Method

    Directory of Open Access Journals (Sweden)

    Baohai Wu

    2013-01-01

    Full Text Available This paper presents a new approach for quick identification of chatter stability lobes with discretization method. Firstly, three different kinds of stability regions are defined: absolute stable region, valid region, and invalid region. Secondly, while identifying the chatter stability lobes, three different regions within the chatter stability lobes are identified with relatively large time intervals. Thirdly, stability boundary within the valid regions is finely calculated to get exact chatter stability lobes. The proposed method only needs to test a small portion of spindle speed and cutting depth set; about 89% computation time is savedcompared with full discretization method. It spends only about10 minutes to get exact chatter stability lobes. Since, based on discretization method, the proposed method can be used for different immersion cutting including low immersion cutting process, the proposed method can be directly implemented in the workshop to promote machining parameters selection efficiency.

  1. Comparison of Naturally Conceived and IVF-DZ Twins in the Netherlands Twin Registry: A Developmental Study

    Directory of Open Access Journals (Sweden)

    Catharina E. M. van Beijsterveldt

    2011-01-01

    Full Text Available In a large set of twin pairs, we compared twins born after IVF to naturally conceived twins with respect to birth characteristics, growth, attainment of motor milestones, and emotional and behavioral problems. Twin families were registered with the Netherlands Twin Register. We included 1534 dizygotic (DZ twins born after IVF, 5315 naturally conceived (NC DZ twins, and 1504 control NC DZ twins who were matched to the IVF twins based on maternal age, maternal educational level, smoking during pregnancy, gestational age, and offspring sex. Data were obtained by longitudinal surveys sent to fathers, mothers, and teachers at ages 1, 2, 3, 7, 10, and 12 years. Results showed no differences in growth, in attainment of motor milestones, and in behavioral development between IVF and matched NC twins. It can be concluded that for nearly all aspects, development in IVF and NC children is similar.

  2. Twin boundary energy and characterization of charge redistribution near the twin boundaries of cupperate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Mahnaz [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Khoshnevisan, Bahram, E-mail: m.mohammadi_2@grad.kashanu.ac.ir [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Javad Hashemifar, S. [Department of Physics, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2014-12-15

    Highlights: • Ab initio simulation for twin boundary energy in YBCO system for the 1st time. • Study of the twin boundary energy variation versus the inserted strain. • Proportionality of twin lamella width by the inserted strain. • Local charge transfer and charge redistribution on the twin planes. • Total DOSs for the twined system at Fermi level is higher than the untwined one. • This explain the effect of twin boundaries in agreement with experimental data. - Abstract: Ab-initio calculations under general gradient approximation have been employed for the first time to find out twin boundary energy, γ, in twined YBCO systems. Despite a vast discrepancy in reported experimental values, our results show that the γ value falls in the range of 40–85 mJ/m{sup 2}. On the other hand, functional form of γ versus inserted strains shows that the mean value for the twin width lamella would tend to approach zero as the strain goes to zero. We have also investigated the local charge transfer and the modification of the electronic states of the basal and twin planes in YBCO, because the charge redistribution at interfaces can modify transport across the grains considerably and determine the applicability of high-T{sub c} superconductors in the electronic applications. The total density of electronic states at the Fermi level for the twined system is enhanced in comparison with the untwined one. Our results explain the influence of twin boundaries in superconductive properties of YBCO, in experimental situations.

  3. Removing the twin image in digital holography by segmented filtering of in-focus twin image

    OpenAIRE

    2008-01-01

    We propose and investigate a new digital method for the reduction of twin-image noise from digital Fresnel holograms. For the case of in-line Fresnel holography the unwanted twin is present as a highly corruptive noise when the object image is numerically reconstructed. We propose to firstly reconstruct the unwanted twin-image when it is in-focus and in this plane we calculate a segmentation mask that borders this in focus image. The twin-image is then segmented and removed by sim...

  4. Rate and Outcomes of Pulmonary Stenosis and Functional Pulmonary Atresia in Recipient Twins with Twin-Twin Transfusion Syndrome.

    Science.gov (United States)

    Ortiz, Javier U; Masoller, Narcís; Gómez, Olga; Bennasar, Mar; Eixarch, Elisenda; Lobmaier, Silvia M; Crispi, Fàtima; Gratacos, Eduard; Martinez, Josep María

    2017-01-01

    To evaluate the rate of pulmonary stenosis and functional pulmonary atresia (PS/PA) in recipient twins prior to fetal surgery for twin-twin transfusion syndrome (TTTS) and their pre- and postnatal outcomes. We carried out a prospective study including 260 cases of TTTS. Echocardiography was performed before laser surgery to detect the presence of PS/PA. The outcomes of recipients with and without PS/PA were compared. The need of postnatal cardiac interventions and the survival rate at 6 months of age were also evaluated. PS was observed in 16/260 (6.2%) of recipient twins and PA in 12/260 (4.6%). After fetal surgery, 10/28 (35.7%) recipients died, 9/28 (32.1%) showed in utero regression, and 9/28 (32.1%) had persistence of PS/PA. Postnatally, seven recipients underwent percutaneous balloon pulmonary valvuloplasty, one required surgical valvotomy and one palliative surgery. Pregnancies with recipient twins with PS/PA had lower survival of at least one twin (67.9 vs. 83.6%, p = 0.045) and lower overall survival (57.1 vs. 72.8%, p = 0.015) at 6 months of age. PS and PA were observed in 10.8% of recipients. Among these, about one third showed persistence of pulmonary valve pathology after delivery, which stresses the need for strict follow-up. © 2016 S. Karger AG, Basel.

  5. Determination of femtosecond-laser-induced refractive-index changes in an optical fiber from far-field measurements

    DEFF Research Database (Denmark)

    Savolainen, Juha-Matti; Grüner-Nielsen, Lars; Kristensen, Poul

    2014-01-01

    A new method for direct writing of localized, circularly symmetric refractive-index changes in optical fibers with a femtosecond laser is demonstrated. The refractive-index changes are characterized using a novel approach employing comparison of numerical simulations to the measured far......-field profiles of unmodified and modified fibers. From the analysis, a negative refractive-index change of −0.015 0.005 within a radius of 0.6 0.1 μm is determined....

  6. Coherent addition of gratings for chirped-pulse-amplified lasers based on near-field and far-field measurements

    Institute of Scientific and Technical Information of China (English)

    Yuchuan Yang; Hui Luo; Xiao Wang; Fuquan Li; Xiaojun Huang; Bin Feng; Feng Jing

    2011-01-01

    @@ The development of phased-array grating compressor is a crucial issue for high-energy, ultra-short pulse petawatt-class lasers.Almost all systems have adopted a tiled-grating approach to meet the size require-ments for the compression gratings.We present a computer-control test system utilizing near-field interfer-ence and far-field focusing capable of monitoring and fast correcting tiled errors of the grating compressor.In this system, the tilt/tip errors between the two gratings are determined by the Fourier transform (FT)of the individual inteiference fringe, and the piston errors are determined by the ratio of the two primary peaks formed in the far-field pattern as a function of the piston difference.Monochromatic grating phasing is achieved experimentally and pulse compression is demonstrated with a tiled grating system.%The development of phased-array grating compressor is a crucial issue for high-energy, ultra-short pulse petawatt-class lasers. Almost all systems have adopted a tiled-grating approach to meet the size requirements for the compression gratings. We present a computer-control test system utilizing near-field interference and far-field focusing capable of monitoring and fast correcting tiled errors of the grating compressor.In this system, the tilt/tip errors between the two gratings are determined by the Fourier transform (FT)of the individual inter ference fringe, and the piston errors are determined by the ratio of the two primary peaks formed in the far-field pattern as a function of the piston difference. Monochromatic grating phasing is achieved experimentally and pulse compression is demonstrated with a tiled grating system.

  7. PET imaging in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Semah, F. [Service Hospitalier Frederic Joliot, DSV-CEA, 91 Orsay (France)

    2006-07-01

    The research projects on epilepsy addressed two main issues: the pathophysiology of the inter-ictal hypo-metabolism in temporal lobe epilepsy and the role of the basal ganglia in the control of seizure. Our research projects focused primarily on temporal lobe epilepsy: The pathophysiology of inter-ictal hypo-metabolism and its correlation with the epileptogenic network was investigated in patients with mesial temporal lobe epilepsy. Inter-ictal hypo-metabolism is commonly found in mesio-temporal lobe epilepsy (MTLE) but its pathophysiology remains incompletely understood. We hypothesized that metabolic changes reflect the preferential networks involved in ictal discharges. We analyzed the topography of inter-ictal hypo-metabolism according to electro-clinical patterns in 50 patients with unilateral hippocampal sclerosis (HS) and consistent features of MTLE. Based on electro-clinical correlations we identified 4 groups:1) mesial group characterized by mesial seizure onset without evidence of early spread beyond the temporal lobe; 2) anterior mesio-lateral group (AML) with early anterior spread, involving the anterior lateral temporal cortex and insulo-fronto-opercular areas; 3) widespread mesio-lateral group (WML) with widespread spread, involving both anterior and posterior lateral temporal and peri-sylvian areas; 4) bi-temporal group (BT) with early contralateral temporal spread. Results of FDG-PET imaging in each group were compared to control subjects using statistical parametric mapping software (SPM99). MRI data and surgical outcome in each group were compared to metabolic findings. Hypo-metabolism was limited to the hippocampal gyrus, the temporal pole and the insula in the mesial group. Gradual involvement of the lateral temporal cortex, the insula and the peri-sylvian areas was observed in the AML and WML groups. The BT group differed from the others by mild bi-temporal involvement, bilateral insular hypo-metabolism and longer epilepsy duration. MRI

  8. Inverse extraction of interfacial tractions from elastic and elasto-plastic far-fields by nonlinear field projection

    Science.gov (United States)

    Chew, Huck Beng

    2013-01-01

    Determining the tractions along a surface or interface from measurement data in the far-fields of nonlinear materials is a challenging inverse problem which has significant engineering and nanoscience applications. Previously, a field projection method was established to identify the crack-tip cohesive zone constitutive relations in an isotropic elastic solid (Hong and Kim, 2003. J. Mech. Phys. Solids 51, 1267). In this paper, the field projection method is further generalized to extracting the tractions along interfaces bounded by nonlinear materials, both with and without pre-existing cracks. The new formulation is based on Maxwell-Betti's reciprocal theorem with a reciprocity gap associated with nonlinear materials. We express the unknown normal and shear tractions along the interface in terms of the Fourier series, and use specially constructed analytical auxiliary fields in the reciprocal theorem to extract the unknown Fourier coefficients from far-field data; the reciprocity gap in the formulation is iteratively determined with a set of numerical algorithms. Our detailed numerical experiments demonstrate that this nonlinear field projection method (NFPM) is well-suited for extracting the interfacial tractions from the far-field data of any nonlinear elastic or elasto-plastic material with known constitutive laws. Applications of the NFPM to experiments and atomistic simulations are discussed.

  9. Cooperative Research Twin Trawl Sweep Comparison Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The "Twin-Trawl Sweep Efficiency Study" was intended to compare the sweep efficiency and selectivity of the NEFSC standardized bottom trawl to that of a standardized...

  10. The Radiative Z2 Breaking Twin Higgs

    CERN Document Server

    Yu, Jiang-Hao

    2016-01-01

    In twin Higgs model, the Higgs boson mass is protected by a $Z_2$ symmetry. The $Z_2$ symmetry needs to be broken either explicitly or spontaneously to obtain misalignment between electroweak and new physics vacua. We propose a novel $Z_2$ breaking mechanism, in which the $Z_2$ is spontaneously broken by radiative corrections to the Higgs potential. Two twin Higgses with different vacua are needed, and vacuum misalignment is realized by opposite but comparable contributions from gauge and Yukawa interactions to the potential. Due to fully radiative symmetry breaking, the Higgs sector is completely determined by twin Higgs vacuum, Yukawa and gauge couplings. There are eight pseudo-Goldstone bosons: the Higgs boson, inert doublet Higgs, and three twin scalars. We show the 125 GeV Higgs mass and constraints from Higgs coupling measurements could be satisfied.

  11. Say No to Fake Twin Brothers

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China vows to fight fake products that exploit a home appliance stimulus project in rural areas Haier Co. Ltd., China’s top home appliance manufacturer, is well known for its logo depicting a pair of twin

  12. Twin Screw Mixer/Fine Grind Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 40-mm Twin-Screw Mixer/Extruder (TSE) pilot plant is a continuous, remotely operated, flexible facility that can significantly enhance safety and environmental...

  13. Cord entanglement in monoamniotic twin pregnancies

    DEFF Research Database (Denmark)

    Lyndrup, J; Schouenborg, Lars Øland

    1987-01-01

    Monoamniotic twin pregnancy involves a heavy risk of fatal umbilical cord entanglement. Two cases are reported. In the first case, both twins were found dead in the 36th week, and the monoamnionicity was recognized at birth. In the second case, the monoamnionicity was discovered during an ultraso......Monoamniotic twin pregnancy involves a heavy risk of fatal umbilical cord entanglement. Two cases are reported. In the first case, both twins were found dead in the 36th week, and the monoamnionicity was recognized at birth. In the second case, the monoamnionicity was discovered during...... an ultrasound examination, and cord entanglement was suspected in the 35th week on the basis of a non-stress test (NST) with variable decelerations. Cesarean section was performed and two healthy children were delivered....

  14. Thoracopagus conjoined twin: an unusual presentation

    Directory of Open Access Journals (Sweden)

    Rajesh Kumari

    2014-02-01

    Full Text Available Conjoined twins are among rare clinical conditions observed by obstetricians. Due to rare incidence of this condition there is general lack of knowledge among obstetricians, especially at primary care level which leads to missed diagnosis during antenatal period. The management of this condition is complex especially in cases where the diagnosis is not known before onset of labour. A 30 - year old Hindu lady was referred to us from other hospital with diagnosis of twin pregnancy and prolonged second stage of labour. Clinical examination revealed findings of ruptured uterus and foetal head of one baby and feet of second baby were outside the introitus. Emergency laparotomy was done which revealed conjoined twins. This article report clinical course of a thoracopagus conjoined twin. The relevant literature is also reviewed. [Int J Reprod Contracept Obstet Gynecol 2014; 3(1.000: 245-247

  15. Twin Cities Metro Hybrid Landcover 2000 (Raster)

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Hybrid Landcover is an attempt to clean up the University of Minnesota Remote Sensing Lab's 2000 LandSat Land Cover for the Twin Cities 7-county metropolitan...

  16. Spectroscopic study of solar twins and analogues

    CERN Document Server

    Datson, Juliet; Portinari, Laura

    2014-01-01

    Context. Many large stellar surveys have been and are still being carried out, providing huge amounts of data, for which stellar physical parameters will be derived. Solar twins and analogues provide a means to test the calibration of these stellar catalogues because the Sun is the best-studied star and provides precise fundamental parameters. Solar twins should be centred on the solar values. Aims. This spectroscopic study of solar analogues selected from the Geneva-Copenhagen Survey (GCS) at a resolution of 48,000 provides effective temperatures and metallicities for these stars. We test whether our spectroscopic parameters, as well as the previous photometric calibrations, are properly centred on the Sun. In addition, we search for more solar twins in our sample. Methods. The methods used in this work are based on literature methods for solar twin searches and on methods we developed in previous work to distinguish the metallicity-temperature degeneracies in the differential comparison of spectra of solar ...

  17. Twin studies: A unique epidemiological tool

    Directory of Open Access Journals (Sweden)

    Monalisha Sahu

    2016-01-01

    Full Text Available Twin studies are a special type of epidemiological studies designed to measure the contribution of genetics as opposed to the environment, to a given trait. Despite the facts that the classical twin studies are still being guided by assumptions made back in the 1920s and that the inherent limitation lies in the study design itself, the results suggested by earlier twin studies have often been confirmed by molecular genetic studies later. Use of twin registries and various innovative yet complex software packages such as the (SAS and their extensions (e.g., SAS PROC GENMOD and SAS PROC PHREG has increased the potential of this epidemiological tool toward contributing significantly to the field of genetics and other life sciences.

  18. Diabetes and Menopause: A Twin Challenge

    Science.gov (United States)

    ... years leading up to it — may present unique challenges if you have diabetes. But it's not necessarily ... while going through menopause can be a twin challenge. Work closely with your doctor to ease the ...

  19. Temporal ghost imaging with twin photons

    Science.gov (United States)

    Denis, Séverine; Moreau, Paul-Antoine; Devaux, Fabrice; Lantz, Eric

    2017-03-01

    We use twin photons generated by spontaneous parametric down conversion to perform temporal ghost imaging of a single time signal. The retrieval of a binary signal containing eight bits is performed with an error rate below 1%.

  20. Prevention of preterm delivery in twin pregnancy.

    Science.gov (United States)

    Rode, Line; Tabor, Ann

    2014-02-01

    The incidence of twin gestation has increased markedly over the past decades, mostly because of increased use of assisted reproductive technologies. Twin pregnancies are at increased risk of preterm delivery (i.e. birth before 37 weeks of gestation). Multiple gestations therefore account for 2-3% of all pregnancies but constitute at least 10% of cases of preterm delivery. Complications from preterm birth are not limited to the neonatal period, such as in retinopathy of prematurity, intraventricular haemorrhage, necrotising enterocolitis, respiratory disorder and sepsis; they can also constitute sequelae such as abnormal neurophysiological development in early childhood and underachievement in school. Several treatment modalities have been proposed in singleton high-risk pregnancies. The mechanism of initiating labour may, however, be different in singleton and twin gestations. Therefore, it is mandatory to evaluate the proposed treatments in randomised trials of multiple gestations. In this chapter, we describe the results of trials to prevent preterm delivery in twin pregnancies.

  1. Infantile Perineal Protrusion in Two Monochorionic Twins

    Directory of Open Access Journals (Sweden)

    Paola Cavicchioli

    2014-11-01

    Full Text Available Case Report - Two female monochorionic-monoamniotic twins showed the same kind of infantile perineal protrusion (IPP at birth. Lesions in both twins progressively healed until resolution in 6 weeks' time; none of the twins have manifested, till date, alvus disturbances. Discussion and Literature Review - A literature review numbers approximately 100 reports of IPP. This condition has been classically classified into three categories: congenital/familiar (i.e., female sex, positive parental history of IPP, acquired (mainly due to constipation, and associated with lichen sclerosus et atrophicus. Conclusions and Final Remarks - This case report describes, for the first time, the presence of IPP in monochorionic-monoamniotic twins, supporting the existence of hereditary/genetic factors in the developing of this condition.

  2. Twin screw subsurface and surface multiphase pumps

    Energy Technology Data Exchange (ETDEWEB)

    Dass, P. [CAN-K GROUP OF COMPANIES, Edmonton, Alberta (Canada)

    2011-07-01

    A new subsurface twin screw multiphase pump has been developed to replace ESP and other artificial lift technologies. This technology has been under development for a few years, has been field tested and is now going for commercial applications. The subsurface twin screw technology consists of a pair of screws that do not touch and can be run with a top drive or submersible motor; and it carries a lot of benefits. This technology is easy to install and its low slippage makes it highly efficient with heavy oil. In addition twin screw multiphase pumps are capable of handling high viscosity fluids and thus their utilization can save water when used in thermal applications. It also induces savings of chemicals because asphaltenes do not break down easily as well as a reduction in SOR. The subsurface twin screw multiphase pump presented herein is an advanced technology which could be used in thermal applications.

  3. Stolen twin: fascination and curiosity/twin research reports: evolution of sleep length; dental treatment of craniopagus twins; cryopreserved double embryo transfer; gender options in multiple pregnancy/current events: appendectomy in one twin; autistic twin marathon runners; 3D facial recognition; twin biathletes.

    Science.gov (United States)

    Segal, Nancy L

    2014-02-01

    The story of her allegedly stolen twin brother in Armenia is recounted by a 'singleton twin' living in the United States. The behavioral consequences and societal implications of this loss are considered. This case is followed by twin research reports on the evolution of sleep length, dental treatment of craniopagus conjoined twins, cryopreserved double embryo transfer (DET), and gender options in multiple pregnancy. Current events include the diagnosis of appendectomy in one identical twin, the accomplishments of autistic twin marathon runners, the power of three-dimensional (3D) facial recognition, and the goals of twin biathletes heading to the 2014 Sochi Olympics in Russia.

  4. Deformation Twinning During Nanoindentation of Nanocrystalline Ta

    OpenAIRE

    Wang, Y. M.; Hodge, A. M.; Biener, J.; Hamza, A.V.; Barnes, D E; Liu, Kai; Nieh, T. G.

    2005-01-01

    The deformation mechanism of body-centered cubic (bcc) nanocrystalline tantalum with grain sizes of 10–30 nm is investigated by nanoindentation, scanning electron microscopy and high-resolution transmission electron microscopy. In a deviation from molecular dynamics simulations and existing experimental observations on other bcc nanocrystalline metals, the plastic deformation of nanocrystalline Ta during nanoindentation is controlled by deformation twinning. The observation of multiple twin i...

  5. Strong crystal size effect on deformation twinning

    DEFF Research Database (Denmark)

    Yu, Qian; Shan, Zhi-Wei; Li, Ju

    2010-01-01

    find that the stress required for deformation twinning increases drastically with decreasing sample size of a titanium alloy single crystal7, 8, until the sample size is reduced to one micrometre, below which the deformation twinning is entirely replaced by less correlated, ordinary dislocation....... The sample size in transition is relatively large and easily accessible in experiments, making our understanding of size dependence11, 12, 13, 14, 15, 16, 17 relevant for applications....

  6. The Twin Research Registry at SRI International.

    Science.gov (United States)

    Krasnow, Ruth E; Jack, Lisa M; Lessov-Schlaggar, Christina N; Bergen, Andrew W; Swan, Gary E

    2013-02-01

    The Twin Research Registry (TRR) at SRI International is a community-based registry of twins established in 1995 by advertising in local media, mainly on radio stations and in newspapers. As of August 2012, there are 3,120 same- and opposite-sex twins enrolled; 86% are 18 years of age or older (mean age 44.9 years, SD 16.9 years) and 14% less than 18 years of age (mean age 8.9 years, SD 4.5); 67% are female, and 62% are self-reported monozygotic (MZ). More than 1,375 twins have participated in studies over the last 15 years in collaboration with the University of California Medical Center in San Francisco, the University of Texas MD Anderson Cancer Center, and the Stanford University School of Medicine. Each twin completes a registration form with basic demographic information either online at the TRR Web site or during a telephone interview. Contact is maintained with members by means of annual newsletters and birthday cards. The managers of the TRR protect the confidentiality of twin data with established policies; no information is given to other researchers without prior permission from the twins; and all methods and procedures are reviewed by an Institutional Review Board. Phenotypes studied thus far include those related to nicotine metabolism, mutagen sensitivity, pain response before and after administration of an opioid, and a variety of immunological responses to environmental exposures, including second-hand smoke and vaccination for seasonal influenza virus and Varicella zoster virus. Twins in the TRR have participated in studies of complex, clinically relevant phenotypes that would not be feasible to measure in larger samples.

  7. Twin birth order, birthweight and birthweight discordance: any relationship

    Directory of Open Access Journals (Sweden)

    Onyiriuka A.N.

    2010-12-01

    Full Text Available Background: It is widely believed that in twin pairs, at birth, the first-born weigh more than the second-born but this concept has been challenged. Objective: To assess the truthfulness of this common concept that first-born twins are usually heavier than their second-born siblings at birth. Methods: In a series of 104 sets of live-born twins, the birth weights of first-born twins were compared with those of their second-born siblings, after controlling for gender. Their intra-pair birthweight differences were determined and twin pairs whose birthweight difference was 15% or more were designated as discordant. Results: Twin I was heavier than Twin II in 61.5% of cases while Twin II was heavier than Twin I in 28.9% of cases. Twins I and II had equal birthweights in 9.6% of cases. Comparing the mean birthweight of the first-born-male twin with that of second-born- male twin, it was 2515+427g (95% Confidence Interval, CI=2402-2628 versus 2432 +435g (95% CI=2321-2543 p>0.05. The mean birthweight of first-born-female twin was 2326+445g (95% CI=2214-2439 while that of the second-born-female twin was 2325+501g (95% CI=2197-2453 p>0.05. When the birthweight difference exceeded 750g, the probability that Twin I will be heavier than Twin II was 83.3% (5 of 6. Conclusion: Although the first-born twin was more often heavier than their second-born siblings, either could weigh more or less at birth. The larger the birthweight difference between growth-discordant twin pair, the greater the probability that the heavier twin would be delivered first

  8. The morphology of the sella turcica in monozygotic twins.

    Science.gov (United States)

    Brock-Jacobsen, Mette T; Pallisgaard, Carsten; Kjaer, Inger

    2009-12-01

    The purpose was to compare the sella turcica morphology of individuals within pairs of monozygotic twins with normal karyotype and to analyze the similarity between the observed morphology and the morphology of non-twins at the same age with normal karyotype. Profile radiographs from 84 individuals of 42 twin pairs (18 male and 24 female pairs, aged 18-23 years) comprised the material. Sella turcica measurements from non-twins aged 6-21 years were used as normal reference. Length, depth and diameter of the sella turcica were measured and controlled by re-measurements. Pearson's correlation coefficient was used for comparison of individuals within twin pairs. For comparison of twins and non-twins, normal standard values for length, depth and diameter were subtracted from the twin values. For the mean values of these differences, confidence limits p values and t values were calculated. The study showed that the size of the sella turcica may be partly similar and partly dissimilar within the pair of monozygotic twins. Statistical evaluation of the data showed correlations between length, depth and diameter of the sella turcica between the two twin individuals in the same twin pair. Differences in sizes are observed between individuals in the twin material and individuals in the non-twin material. As a conclusion, the twin males were more similar within the twin pair, but deviated more from the non-twin material than the females. Female twins had more discrepancy within the twin pair, but deviated less from the non-twin material than the males.

  9. Exotic Quarks in Twin Higgs Models

    CERN Document Server

    Cheng, Hsin-Chia; Salvioni, Ennio; Tsai, Yuhsin

    2015-01-01

    The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ~ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of the model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles ...

  10. Urticaria in monozygotic and dizygotic twins

    DEFF Research Database (Denmark)

    Thomsen, Simon Francis; van der Sluis, Sophie; Kyvik, Kirsten Ohm

    2012-01-01

    Aim. To identify risk factors for urticaria, to determine the relative proportion of the susceptibility to urticaria that is due to genetic factors in an adult clinical twin sample, and to further determine whether the genetic susceptibility to urticaria overlaps with the genetic susceptibility...... to atopic diseases. Methods. A total of 256 complete twin pairs and 63 single twins, who were selected from sibships with self-reported asthma via a questionnaire survey of 21,162 adult twins from the Danish Twin Registry, were clinically interviewed about a history of urticaria and examined for atopic.......36-2.72), P = 0.000; and atopic dermatitis, HR = 1.44 (1.02-2.06), P = 0.041 were significant risk factors for urticaria. After adjustment for sex and age at onset of urticaria in the index twin, the risk of urticaria was increased in MZ cotwins relative to DZ cotwins, HR = 1.42 (0.63-3.18), P = 0...

  11. Acoustic Emission of Deformation Twinning in Magnesium

    Directory of Open Access Journals (Sweden)

    Chengyang Mo

    2016-08-01

    Full Text Available The Acoustic Emission of deformation twinning in Magnesium is investigated in this article. Single crystal testing with combined full field deformation measurements, as well as polycrystalline testing inside the scanning electron microscope with simultaneous monitoring of texture evolution and twin nucleation were compared to testing at the laboratory scale with respect to recordings of Acoustic Emission activity. Single crystal testing revealed the formation of layered twin boundaries in areas of strain localization which was accompanied by distinct changes in the acoustic data. Testing inside the microscope directly showed twin nucleation, proliferation and growth as well as associated crystallographic reorientations. A post processing approach of the Acoustic Emission activity revealed the existence of a class of signals that appears in a strain range in which twinning is profuse, as validated by the in situ and ex situ microscopy observations. Features extracted from such activity were cross-correlated both with the available mechanical and microscopy data, as well as with the Acoustic Emission activity recorded at the laboratory scale for similarly prepared specimens. The overall approach demonstrates that the method of Acoustic Emission could provide real time volumetric information related to the activation of deformation twinning in Magnesium alloys, in spite of the complexity of the propagation phenomena, the possible activation of several deformation modes and the challenges posed by the sensing approach itself when applied in this type of materials evaluation approach.

  12. Imperfect twinning: a clinical and ethical dilemma

    Science.gov (United States)

    Denardin, Daniela; Telles, Jorge Alberto B.; Betat, Rosilene da Silveira; Fell, Paulo Renato K.; da Cunha, André Campos; Targa, Luciano Vieira; Zen, Paulo Ricardo G.; Rosa, Rafael Fabiano M.

    2013-01-01

    OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. DATA SYNTHESIS: The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family. PMID:24142323

  13. Laying the ghost of twin paradox

    Directory of Open Access Journals (Sweden)

    Popović Marko

    2009-01-01

    Full Text Available Someone's true age is not written in his ID, but in his biomarkers. Aging process is not caused by time passing, but by thermodynamically laws. Entropy, extent of metabolic reaction, and temperature are Lorentz invariant, so these facts make twin paradox impossible because there is no way for one twin to age slower than the other even if the time in his frame is dilated. Entropy is the function of state, not time. So as much as standard thermodynamics concerns, the path between two points in space is equivalent to the path between two states. Whether the point B is reached by moving faster using the longer way (with time dilatation, or slower by using shortcut (without time dilatation, the state of the system after completing the road should be the same. This is supported by the fact that when two twins reach the same space-time point (point B in which the state parameters are the same. If we use entropy as an age parameter, then both twins have the same entropy value and are exactly the same biological age. Therefore, the twin paradox is a logical mistake based on wrong first premise. Bergson symmetry is not necessary any more to explain the impossibility of twin paradox.

  14. Imperfect twinning: a clinical and ethical dilemma.

    Science.gov (United States)

    Denardin, Daniela; Telles, Jorge Alberto B; Betat, Rosilene da Silveira; Fell, Paulo Renato K; Cunha, André Campos da; Targa, Luciano Vieira; Zen, Paulo Ricardo G; Rosa, Rafael Fabiano M

    2013-09-01

    OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family.

  15. The Finnish Twin Cohort Study: an update.

    Science.gov (United States)

    Kaprio, Jaakko

    2013-02-01

    In 2002 and 2006, review papers have described the Finnish Twin Cohort and studies conducted on these population-based, longitudinal data sets with extensive follow-up data. Three cohorts have been established: the older twin cohort in the 1970s, and the Finntwin12 and Finntwin16 studies initiated in the 1990s. The present review provides on update on the latest data collections conducted since the previous review. These cover the fourth waves of data collection in the older cohort (twins born before 1958) and Finntwin12 (twins born 1983-1987). The fifth wave of data collection in Finntwin16 (twins born 1975-1979) also included assessments of their spouses/partners. An analysis of mortality in the older cohort from 1975 to 2009 indicates that the mortality of adult twins (as individuals) does not differ from the population at large. Based on the cohorts, many sub-studies with more detailed phenotyping and collection of omics data have been conducted or are in progress. We also contribute to numerous national and international collaborations.

  16. Imperfect twinning: a clinical and ethical dilemma

    Directory of Open Access Journals (Sweden)

    Daniela Denardin

    2013-09-01

    Full Text Available OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. DATA SYNTHESIS: The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family.

  17. Twin pregnancy in the congenital malformed uterus.

    Science.gov (United States)

    Heinonen, Pentti K

    2016-07-01

    The frequency and outcome of twin pregnancies in women with uterine malformation were studied. The cohort comprised 13 (4.9%) women with twin pregnancy found among 263 women. They had 483 deliveries, 13 of them twins (2.7%; 95% CI 1.6-4.6%). Among 38 patients with unicornuate uterus 5 (6.8%) out of 74 deliveries were twins, 39 women with didelphic uterus 2 (3.2%) out of 62 deliveries and 147 women with septate or subseptate uterus 6 (2.3%) out of 264 deliveries were twins. The mean duration of gestation was 249 days (range 190-268 days), 5 (38%) out of 13 deliveries were premature, 25 out of 26 newborns were alive. Mean durations of gestation and mean weights of newborns did not differ when 7 cases with unicornuate or didelphic uterus were compared to 6 cases with complete or partial uterine septum. A congenital malformed uterus can bear twin pregnancy without severe complications apart from prematurity.

  18. Thermo-mechanical modeling of continental rift evolution over mantle upwelling in presence of far-field stresses

    Science.gov (United States)

    Koptev, Alexander; Burov, Evgueni; Calais, Eric; Leroy, Sylvie; Gerya, Taras

    2016-04-01

    We conducted fully-coupled high resolution rheologically consistent 3D thermo-mechanical numerical models to investigate the processes of mantle-lithosphere interaction (MLI) in presence of preexisting far-field tectonic stresses. MLI-induced topography exhibits strongly asymmetric small-scale 3D features, such as rifts, flexural flank uplifts and complex faults structures. This suggests a dominant role of continental rheological structure and intra-plate stresses in controlling continental rifting and break-up processes above mantle upwelling while reconciling the passive (far-field tectonic stresses) versus active (plume-activated) rift concepts as our experiments show both processes in action. We tested different experiments by varying two principal controlling parameters: 1) horizontal extension velocity and 2) Moho temperature used as simplified indicator of the thermal and rheological lithosphere layering. An increase in the applied extension expectedly gives less localized deformation at lithospheric scale: the growth of external velocity from 1.5 mm/years to 6 mm/years leads to enlargement of the rift zones from 75-175 km to 150-425 km width. On the contrary, increasing of the lithospheric geotherm has an opposite effect leading to narrowing of the rift zone: the change of the Moho isotherm from 600°C to 800°C causes diminution of the rift width from 175-425 km to 75-150 km. Some of these finding are contra-intuitive in terms of usual assumptions. The models refer to strongly non-linear impact of far-field extension rates on timing of break-up processes. Experiments with relatively fast far-field extension (6 mm/years) show intensive normal fault localization in crust and uppermost mantle above the plume head at 15-20 Myrs after the onset of the experiment. When plume head material reaches the bottom of the continental crust (at 25 Myrs), the latter is rapidly ruptured (crust bottom). We conclude from our modeling that localization of large-scale linear

  19. Salivary cortisol in unaffected twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Vinberg, Maj; Bennike, Bente; Kyvik, Kirsten Ohm

    2008-01-01

    -sectional high-risk study. Healthy monozygotic (MZ) and dizygotic (DZ) twins with (High-Risk twins) and without (Low-Risk twins) a co-twin history of affective disorder were identified through nationwide registers. Awakening and evening salivary cortisol levels were compared between the 190 High- and Low......-Risk twins. The 109 High-Risk twins had significantly higher evening cortisol levels than the 81 Low-Risk MZ twins, also after adjustment for age, sex, and the level of subclinical depressive symptoms. No significant difference was found in awakening cortisol levels between High-Risk and Low-Risk twins....... In conclusion, a high genetic liability to affective disorder was associated with a higher evening cortisol level, but not with awakening cortisol level. Future prospective family, high-risk and twin studies are needed to decide whether abnormalities in the HPA axis can be identified as an endophenotype...

  20. Extrahippocampal Desynchronization in Nonlesional Temporal Lobe Epilepsy

    Directory of Open Access Journals (Sweden)

    Jesús Pastor

    2012-01-01

    Full Text Available Although temporal lobe epilepsy (TLE is traditionally associated with both hypersynchronous activity in the form of interictal epileptic discharges and hippocampal sclerosis, recent findings suggest that desynchronization also plays a central role in the dynamics of this pathology. The objective of this work is to show the imbalance existing between mesial activities in patients suffering from mesial TLE, with normal mesial structures. Foramen ovale recordings from six patients with mesial TLE and one with lateral TLE were analyzed through a cluster analysis and synchronization matrices. None of the patients present findings in the MRI presurgical evaluation. Numerical analysis was carried out in three different situations: awake and sleep interictal and also during the preictal stage. High levels of desynchronization ipsilateral to the epileptic side were present in mesial TLE patients. Low levels of desynchronization were present in the lateral TLE patient during the interictal stage and almost zero in the preictal stage. Implications of these findings in relation with seizure spreading are discussed.

  1. Probabilistic Tsunami Hazard in the NE Atlantic from Near- and Far-field Tectonic Sources

    Science.gov (United States)

    Omira, R.; Baptista, M.; Matias, L.; Carrilho, F.; Miranda, J. M.

    2012-12-01

    A comprehensive assessment of the hazard posed by tsunamis must include an evaluation of the possible tsunami impact from near- and far-field sources as well as its likelihood of occurrence. In the NE Atlantic region, tsunami hazard assessment has been mainly performed through deterministic approaches considering regional most credible earthquake scenarios. This work focuses on the probabilistic approach for tsunami hazard assessment in the NE Atlantic region. The advantage of such approach consists of yielding information on the likelihood of tsunami impact in addition to the other components of hazard assessment (wave heights, inundation, run-up…etc). Probabilistic tsunami hazard assessment approach, used here, integrates tsunami waveform and inundation modeling with probabilistic seismic hazard assessment methods. This approach consists of various steps: i) identification of tsunami sources and assessment of their annual rates of recurrence; ii) Numerical simulations of near-shore waveform and flooding; iii) Evaluation of the probability exceedance for wave heights and inundations for a given period of time; vi) Derivation of tsunami hazard curves. Both near- and far-field seismic sources able to trigger tsunamis that reach/affect the NE Atlantic coasts are considered in order to generate a set of credible scenarios for the region. This database incorporates various magnitude ranges of possible earthquakes generated at the potential tsunamigenic zones from the Gulf of Cadiz to the Caribbean. The annual recurrence rate of each magnitude range is derived through the Bayesian method that incorporates seismic information from historical catalog and instrumental periods for the Gulf of Cadiz, while we will use only instrumental information for the Caribbean source area. A numerical code, solving shallow water equations in their linear and non linear forms, is then employed to simulate the tsunami propagation and flooding resulting from the occurrence of the

  2. Sea-level probability for the last deglaciation: A statistical analysis of far-field records

    Science.gov (United States)

    Stanford, J. D.; Hemingway, R.; Rohling, E. J.; Challenor, P. G.; Medina-Elizalde, M.; Lester, A. J.

    2011-12-01

    Pulses of ice-sheet meltwater into the world ocean during the last deglaciation are of great current interest, because these large-scale events offer important test-beds for numerical models of the responses of ocean circulation and climate to meltwater addition. The largest such event has become known as meltwater pulse (mwp) 1a, with estimates of about 20 m of sea-level rise in about 500 years. A second meltwater pulse (mwp-1b) has been inferred from some sea-level records, but its existence has become debated following the presentation of additional records. Even the use of the more ubiquitous mwp-1a in modelling studies has been compromised by debate about its exact age, based upon perceived discrepancies between far-field sea-level records. It is clear that an objective investigation is needed to determine to what level inferred similarities and/or discrepancies between the various deglacial sea-level records are statistically rigorous (or not). For that purpose, we present a Monte Carlo style statistical analysis to determine the highest-probability sea-level history from six key far-field deglacial sea-level records, which fully accounts for realistic methodological and chronological uncertainties in all these records, and which is robust with respect to removal of individual component datasets. We find that sea-level rise started to accelerate into the deglaciation from around 17 ka BP. Within the deglacial rise, there were two distinct increases; one at around the timing of the Bølling warming (14.6 ka BP), and another, much broader, event that just post-dates the end of the Younger Dryas (11.3 ka BP). We interpret these as mwp-1a and mwp-1b, respectively. We find that mwp-1a occurred between 14.3 ka BP and 12.8 ka BP. Highest rates of sea-level rise occurred at ~ 13.8 ka, probably (67% confidence) within the range of 100-130 cm/century, although values may have been as high as 260 cm/century (99% confidence limit). Mwp-1b is robustly expressed as a broad

  3. Linking near- and far-field hydrodynamic models for simulation of desalination plant brine discharges.

    Science.gov (United States)

    Botelho, D A; Barry, M E; Collecutt, G C; Brook, J; Wiltshire, D

    2013-01-01

    A desalination plant is proposed to be the major water supply to the Olympic Dam Expansion Mining project. Located in the Upper Spencer Gulf, South Australia, the site was chosen due to the existence of strong currents and their likely advantages in terms of mixing and dilution of discharged return water. A high-resolution hydrodynamic model (Estuary, Lake and Coastal Ocean Model, ELCOM) was constructed and, through a rigorous review process, was shown to reproduce the intricate details of the Spencer Gulf dynamics, including those characterising the discharge site. Notwithstanding this, it was found that deploying typically adopted 'direct insertion' techniques to simulate the brine discharge within the hydrodynamic model was problematic. Specifically, it was found that in this study the direct insertion technique delivered highly conservative brine dilution predictions in and around the proposed site, and that these were grid and time-step dependent. To improve the predictive capability, a strategy to link validated computational fluid dynamics (CFD) predictions to hydrodynamic simulations was devised. In this strategy, environmental conditions from ELCOM were used to produce boundary conditions for execution of a suite of CFD simulations. In turn, the CFD simulations provided the brine dilutions and flow rates to be applied in ELCOM. In order to conserve mass in a system-wide sense, artificial salt sinks were introduced to the ELCOM model such that salt quantities were conserved. As a result of this process, ELCOM predictions were naturally very similar to CFD predictions near the diffuser, whilst at the same time they produced an area of influence (further afield) comparable to direct insertion methods. It was concluded that the linkage of the models, in comparison to direct insertion methods, constituted a more realistic and defensible alternative to predict the far-field dispersion of outfall discharges, particularly with regards to the estimation of brine

  4. Mach Cutoff Analysis and Results from NASA's Farfield Investigation of No-Boom Thresholds

    Science.gov (United States)

    Cliatt, Larry J., II; Hill, Michael A.; Haering, Edward A., Jr.

    2016-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center, in partnership with other industry organizations and academia, conducted a flight research experiment to analyze acoustic propagation in the Mach cutoff shadow zone. The effort was conducted in the fall of 2012 and named the Farfield Investigation of No-boom Thresholds (FaINT). The test helped to build a dataset that will go toward further understanding of the unique acoustic propagation characteristics below Mach cutoff altitude. FaINT was able to correlate sonic boom noise levels measured below cutoff altitude with precise airplane flight conditions, potentially increasing the accuracy over previous studies. A NASA F-18B airplane made supersonic passes such that its Mach cutoff caustic would be at varying distances above a linear 60-microphone, 7375-ft (2247.9 m) long array. A TG-14 motor glider equipped with a microphone on its wing-tip also attempted to capture the same sonic boom waves above ground, but below the Mach cutoff altitude. This paper identified an appropriate metric for sonic boom waveforms in the Mach cutoff shadow zone called Perceived Sound Exposure Level; derived an empirical relationship between Mach cutoff flight conditions and noise levels in the shadow zone; validated a safe cutoff altitude theory presented by previous studies; analyzed the sensitivity of flight below Mach cutoff to unsteady atmospheric conditions and realistic aircraft perturbations; and demonstrated the ability to record sonic boom measurements over 5000 ft (1524.0 m) above ground level, but below Mach cutoff altitude.

  5. Severe preeclampsia cured by heparin in a patient with twin-twin transfusion syndrome

    Institute of Scientific and Technical Information of China (English)

    CHU Hong-nü; ZHOU Cai-yun

    2007-01-01

    @@ Heparin therapy for preeclampsia has been reported frequently.1-3 Most of the authors used heparin to prevent thrombosis and achieved good results. But its mechanism is not clear.4 Here we describe a case of severe early-onset preeclampsia complicated with hypercoagulable state, fetal growth restriction, and twin-twin transfusion syndrome, that responded well to heparin.

  6. Decreased frontal lobe function in people with Internet addiction disorder

    Institute of Scientific and Technical Information of China (English)

    Jun Liu; Shunke Zhou; Fatema Esmail; Lingjiang Li; Zhifeng Kou; Weihui Li; Xueping Gao; Zhiyuan Wang; Changlian Tan; Yan Zhang

    2013-01-01

    In our previous studies, we showed that frontal lobe and brainstem functions were abnormal in on-line game addicts. In this study, 14 students with Internet addiction disorder and 14 matched healthy controls underwent proton-magnetic resonance spectroscopy to measure cerebral function. Results demonstrated that the ratio of N-acetylaspartate to creatine decreased, but the ratio of cho-line-containing compounds to creatine increased in the bilateral frontal lobe white matter in people with Internet addiction disorder. However, these ratios were mostly unaltered in the brainstem, suggesting that frontal lobe function decreases in people with Internet addiction disorder.

  7. Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Tae Kwan; Kim, Dong Wook; Park, Ha Kyoung; Jung, Soo Jin [Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-12-15

    We report an extremely rare case of papillary thyroid microcarcinoma (PTMC) in the thyroid pyramidal lobe (TPL). A 48-year-old woman underwent ultrasound-guided fine-needle aspiration for a small thyroid nodule in the right lobe in local clinic, and it revealed a malignant cytology. On preoperative ultrasonography for tumor staging in our hospital, another small suspiciously malignant hypoechoic nodule was detected in the left TPL. Total thyroidectomy and central nodal dissection were performed. Histopathology confirmed PTMCs in the left TPL and both thyroid lobes. Ultrasonography for TPL should be required for complete evaluation of possible multifocality of thyroid malignancy.

  8. Papillary Carcinoma Arising from the Pyramidal Lobe of the Thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Gi; Lee, Sarah; Kim, Eun Kyung; Moon, Hee Jung; Kwak, Jin Young [Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2012-03-15

    The authors present a rare case of papillary carcinoma arising from the pyramidal lobe of the thyroid in a 54-year-old woman, who presented with a right submental palpable mass. An ultrasound evaluation depicted a 3 cm mixed echoic mass from the thyroid cartilage level without a focal lesion in the thyroid gland. Surgical specimens obtained during bilateral thyroidectomy confirmed papillary carcinoma of the pyramidal lobe. To the authors' knowledge, this is the first case report to describe papillary carcinoma arising from the pyramidal lobe of the thyroid gland

  9. Art for twins: Yorùbá artists and their statues/twin research studies: twins' education and conceptions; diurnal preference; inherited eye diseases; ultrasound counseling when twins are conjoined/popular twin reports: twin sisters (the film); rare pregnancy; diet test; French twins reared apart and reunited.

    Science.gov (United States)

    Segal, Nancy L

    2014-06-01

    The Yorùbá of Nigeria are well known for their high twinning rate and the statues they create to commemorate deceased twins. An impressive collection of this artwork was displayed at the University of California's Fowler Museum in Los Angeles between October 13, 2013 and March 2, 2014. An overview of this exhibit is provided. Next, twin research on maternal education and conception, diurnal preference, inherited eye diseases, and ultrasound counseling for couples with conjoined twins are briefly summarized. This article concludes with a discussion of media-based items related to twins. The topics include an award-winning twin film, a rare pregnancy, a diet test, and the separation and chance reunion of monozygotic female twins.

  10. Niobium and tantalum: indispensable twins

    Science.gov (United States)

    Schulz, Klaus; Papp, John

    2014-01-01

    Niobium and tantalum are transition metals almost always paired together in nature. These “twins” are difficult to separate because of their shared physical and chemical properties. In 1801, English chemist Charles Hatchett uncovered an unknown element in a mineral sample of columbite; John Winthrop found the sample in a Massachusetts mine and sent it to the British Museum in London in 1734. The name columbium, which Hatchet named the new element, came from the poetic name for North America—Columbia—and was used interchangeably for niobium until 1949, when the name niobium became official. Swedish scientist Anders Ekberg discovered tantalum in 1802, but it was confused with niobium, because of their twinned properties, until 1864, when it was recognized as a separate element. Niobium is a lustrous, gray, ductile metal with a high melting point, relatively low density, and superconductor properties. Tantalum is a dark blue-gray, dense, ductile, very hard, and easily fabricated metal. It is highly conductive to heat and electricity and renowned for its resistance to acidic corrosion. These special properties determine their primary uses and make niobium and tantalum indispensable.

  11. Spondyloepiphyseal Dysplasia Tarda in Twins

    Directory of Open Access Journals (Sweden)

    Ferhat Çekmez

    2011-08-01

    Full Text Available Introduction: Spondyloepiphyseal dysplasia (SED is a genetically heterogeneous disorder often associated with the early onset of osteoarthrosis. The X-linked recessive form (SEDL affects boys and is characterized by reduced height, arm span exceeding total height, and barrel chest deformity. The radiographic phenotype comprises a hump-shaped deformity of vertebral bodies and mild epiphyseal dysplasia of the femoral head associated with early signs of hip arthrosis.The disorder is caused by mutations in the SEDL (or sedlin gene on Xp22.12-p22.31. SED should be kept in mind as a differential diagnosis in men with early “primary” bilateral osteoarthrosis.Case Report: Here, 11 years old twins diagnosed as SED due to walking disability, limitation of joint motion, pain at the hips and disability in standing for a long time were presented. Discussion: This rare skelatal dysplasia must be kept in mind in patients with painful spine and hip joints, and walking disability. (Jo­ur­nal of Cur­rent Pe­di­at­rics 2011; 9: 97-9

  12. Situs Inversus Totalis in Twins: A Brief Review and a Life History / Twin Research: Twin Studies of Trisomy 21; Monozygotic Twin Concordance for Bilateral Coronoid Hyperplasia; Prenatal Hormonal Effects in Mixed-Sex Non-Human Primate Litters; Insurance Mandates and Twinning After In Vitro Fertilization / News Reports: First Report of Identical Twin Puppies; Twins Sisters Turn 100; Remembering an Identical Twin Production Designer; New York City Marathon Quadruplets.

    Science.gov (United States)

    Segal, Nancy L

    2017-02-01

    The presence of situs inversus totalis (full reversal of internal organs) in twins is briefly reviewed. Information gathered from 35-year-old monozygotic (MZ) female twin pair discordant for this condition is presented. This is followed by summaries of research on the frequency of trisomy 21 (Down syndrome) in twins, the first case of MZ twin concordance for bilateral coronoid hyperplasia, prenatal hormonal effects in mixed-sex non-human primate litters, and links between insurance mandates and twinning following in vitro fertilization. The final section of this article describes twin-related events reported in the news, namely, the first recorded birth of identical twin puppies; the 100th birthday celebration of a pair of fraternal female twins, the passing of an award-winning identical twin production designer, and the first running of the New York City Marathon by a set of quadruplets.

  13. Attachment to the Romantic Partner and Sibling: Attachment Hierarchies of Twins and Non-Twin Siblings

    Directory of Open Access Journals (Sweden)

    Sascha Schwarz

    2015-12-01

    Full Text Available Previous studies have shown that romantic partners and siblings are important attachment figures. This study compares the attachment to the romantic partner with the attachment to the sibling as a function of the participant’s sibling type among monozygotic (MZ twins, dizygotic (DZ twins, and non-twin (NT siblings. The results show that MZ twins prefer their sibling to their romantic partner whereas DZ twins are equally attached to their sibling and romantic partner. In contrast, NT siblings are more attached to their romantic partner compared to their sibling. These results indicate that genetic relatedness has profound impact on a person’s attachment hierarchy and the relative rank of the romantic partner and the sibling.

  14. A registry of adult African American twins: the Carolina African American Twin Study of Aging.

    Science.gov (United States)

    Whitfield, Keith E

    2013-02-01

    Twin studies have seldom addressed ethnicity as one of the possible factors that create unique combinations of genetic and environmental influences. The major objective of the Carolina African American Twin Study of Aging is to identify the proportion of the genetic and environmental sources of individual variation in measures of health and behavioral factors in a sample of adult African Americans. Drawn from birth records from the State of North Carolina, this in-person study used public records to identify a cohort of twins between 22 and 92 years of age (X = 49.82 yrs, SD = 14.62), 39.7% of which were men. Members of non-intact twin pairs and siblings were also recruited to explore alternative models to the classic twin design. To date, the project has contributed to knowledge about blood pressure, forced expiratory volume, chronic illness, body mass index, and waist-hip ratio memory, personality, social, and demographic factors, mortality, and mental health.

  15. Treatment of twin-twin transfusion syndrome by fetoscopic laser photocoagulation

    Institute of Scientific and Technical Information of China (English)

    劉子建; 梁德楊; 馮德源; 梁子昂

    2004-01-01

    @@ Twin-twin transfusion syndrome (TTTS) is a serious obstetric complication, occurring in about 15% of monochorionic (MC) twin pregnancies. If untreated, the prognosis is poor, with an overall perinatal mortality of 80%.1 It is now clear that TTTS is the result of an unbalanced unidirectional blood flow through placental arteriovenous anastomoses (also termed deep anastomoses) between the two fetal circulations.2 The donor twin progressively becomes anemic, and develops growth restriction, oliguria, and oligohydramnios/anhydramnios; whereas the recipient becomes plethoric and polyuric, and develops congestive heart failure, cardiomegaly, polyhydramnios and fetal hydrops. Preterm labor is common because of gross polyhydramnios, and further deteriorations will lead to intrauterine death of both twins.

  16. Atopic diseases in twins born after assisted reproduction

    DEFF Research Database (Denmark)

    Jäderberg, Ida; Thomsen, Simon F; Kyvik, Kirsten Ohm

    2012-01-01

    Jäderberg I, Thomsen SF, Kyvik KO, Skytthe A, Backer V. Atopic diseases in twins born after assisted reproduction. Paediatric and Perinatal Epidemiology 2012; 26: 140-145. We examined the risk of atopic diseases in twins born after assisted reproduction. Data on atopic diseases and assisted...... reproduction in 9694 twin pairs, 3-20 years of age, from the Danish Twin Registry were collected via multidisciplinary questionnaires. The risk of atopic diseases in twins born after assisted reproduction was compared with the risk in twins born after spontaneous conception using logistic regression...

  17. Diabetes and perinatal mortality in twin pregnancies.

    Directory of Open Access Journals (Sweden)

    Zhong-Cheng Luo

    Full Text Available BACKGROUND: Diabetes in pregnancy has been associated with a paradoxically reduced risk of neonatal death in twin pregnancies. Risk "shift" may be a concern in that the reduction in neonatal deaths may be due to an increase in fetal deaths (stillbirths. This study aimed to clarify the impact of diabetes on the risk of perinatal death (neonatal death plus stillbirth in twin pregnancies. METHODS: This was a retrospective cohort study of twin births using the largest available dataset on twin births (the U.S. matched multiple birth data 1995-2000; 19,676 neonates from diabetic pregnancies, 541,481 from non-diabetic pregnancies. Cox proportional hazard models were applied to estimate the adjusted hazard ratios (aHR of perinatal death accounting for twin cluster-level dependence. RESULTS: Comparing diabetic versus non-diabetic twin pregnancies, overall perinatal mortality rate was counterintuitively lower [2.1% versus 3.3%, aHR 0.70 (95% confidence intervals 0.63-0.78]. Individually, both stillbirth and neonatal mortality rates were lower in diabetic pregnancies, but we identified significant differences by gestational age and birth weight. Diabetes was associated with a survival benefit in pregnancies completed before 32 weeks [aHR 0.55 (0.48-0.63] or with birth weight =2500 g [aHR 2.20 (1.55-3.13]. CONCLUSIONS: Diabetes in pregnancy appears to be "protective" against perinatal death in twin pregnancies ending in very preterm or very low birth weight births. Prospective studies are required to clarify whether these patterns of risk are real, or they are artifacts of unmeasured confounders. Additional data correlating these outcomes with the types of diabetes in pregnancy are also needed to distinguish the effects of pre-gestational vs. gestational diabetes.

  18. DNA stability and schizophrenia in twins.

    Science.gov (United States)

    Nguyen, Giang H; Bouchard, Joseph; Boselli, Monica G; Tolstoi, Linda G; Keith, Louis; Baldwin, Clinton; Nguyen, Nam C; Schultz, Mark; Herrera, Victoria L M; Smith, Cassandra L

    2003-07-01

    The goal of these experiments was to understand DNA changes relevant to schizophrenia. This work compared DNA of monozygotic (MZ) twins surrounding (CAG)(n) repeating sequences, and characterized the relationship between fragile sites and schizophrenia. Twelve twin-pairs, previously classified as MZ and 18 unrelated sib-pairs, from seven families were studied. Eight twin-pairs were affected by schizophrenia, four concordantly and four discordantly. DNA comparisons were made using profiles of electrophoretic size fractionations of PCR amplified (CAG)(n) containing genomic fragments. These profiles were generated by a new method, developed by us, called targeted genomic differential display (TGDD). Surprisingly, the number of peak profile differences in MZ twin-pairs discordant for schizophrenia was greater than the concordantly ill twins and the well twins and, in some cases, overlapped the range of sib-pairs. These results might mean that some twins were not MZ but it was not possible to definitively test these samples for zygosity. Alternatively, the results might be explained as an increased mutation rate (or genomic instability) around (CAG)(n) sites in individuals afflicted with schizophrenia. Also, we uncovered an association of schizophrenia (i.e., a linkage of chromosomal abnormalities and gene localizations) with fragile sites spread throughout the genome (chi(2), P = 0.001). Furthermore, it appears that an increasing number of genes linked to schizophrenia are associated with (CAG)(n) sequences. Fragile sites and (CAG)(n) repeat sequences are known to be unstable. We speculate the association of genomic instability with schizophrenia accounts for seemingly disparate biological and environmental factors that influence disease occurrence. Copyright 2003 Wiley-Liss, Inc.

  19. Twin studies in auto-immune disease.

    Science.gov (United States)

    Leslie, R D; Hawa, M

    1994-01-01

    Immune-mediated diseases affect up to 5% of the population and are a major cause of morbidity and mortality. These diseases can be organ specific, such as insulin-dependent diabetes (IDDM) and non-organ specific, such as Rheumatoid Arthritis (RA). Identical and non-identical twins have been used to establish whether these diseases are determined by genetic or environmental factors. The results of these studies have been collated in a new section of the Mendel Institute in Rome. Diseases included in these studies included IDDM, RA, Systemic Lupus Erythematosus (SLE), Multiple Sclerosis (MS) and Myasthenia. Striking differences in concordance rates between identical and non-identical twins in all these studies suggest that genetic factors are important in causing these diseases. All the diseases are known to be associated with HLA genes on chromosome 6 which may account for some or all of the genetic susceptibility. However, in the majority of pairs the affected twin has an unaffected co-twin. These observations suggest that non-genetically determined factors, probably environmental factors and not somatic mutations, are critical. The study of unaffected co-twins, who are at high disease-risk, has allowed the identification of changes which precede and predict the clinical disease. The immune-mediated destruction in many of these diseases is probably caused by T-lymphocytes. Twin studies have shown the importance of genetic factors in determining T-cell responses. Identical twins should, therefore, provide the perfect test bed to assess the role of T-cells in immune-mediated diseases.

  20. Medial temporal lobe and topographical memory.

    Science.gov (United States)

    Urgolites, Zhisen J; Hopkins, Ramona O; Squire, Larry R

    2017-08-08

    There has been interest in the idea that medial temporal lobe (MTL) structures might be especially important for spatial processing and spatial memory. We tested the proposal that the MTL has a specific role in topographical memory as assessed in tasks of scene memory where the viewpoint shifts from study to test. Building on materials used previously for such studies, we administered three different tasks in a total of nine conditions. Participants studied a scene depicting four hills of different shapes and sizes and made a choice among four test images. In the Rotation task, the correct choice depicted the study scene from a shifted perspective. MTL patients succeeded when the study and test images were presented together but failed the moment the study scene was removed (even at a 0-s delay). In the No-Rotation task, the correct choice was a duplicate of the study scene. Patients were impaired to the same extent in the No-Rotation and Rotation tasks after matching for difficulty. Thus, an inability to accommodate changes in viewpoint does not account for patient impairment. In the Nonspatial-Perceptual task, the correct choice depicted the same overall coloring as the study scene. Patients were intact at a 2-s delay but failed at longer, distraction-filled delays. The different results for the spatial and nonspatial tasks are discussed in terms of differences in demand on working memory. We suggest that the difficulty of the spatial tasks rests on the neocortex and on the limitations of working memory, not on the MTL.

  1. Ectopic neuroblastoma in monozygotic twins with different ages of onset: possible twin-to-twin metastasis in utero with distinct genetic alterations after birth.

    Science.gov (United States)

    Taketani, Takeshi; Takita, Junko; Ueyama, Junichi; Kanai, Rie; Kumori, Koji; Maruyama, Riruke; Hayashi, Kazuhiko; Ogawa, Seishi; Fukuda, Seiji; Yamaguchi, Seiji

    2014-03-01

    We describe neuroblastoma (NB) in monozygotic twins whose ages at the onset of the disease had a 3-year interval. The primary tumor site of twin 1 was the adrenal gland, whereas that of twin 2 was the jejunum/mesentery. MYCN amplification, DNA index, ALK mutation, and copy number alterations of DNA were different between each primary tumor. NB in ectopic sites may have resulted from twin-to-twin metastasis through vascular anastamoses in the placenta. The pathogenesis of this NB involved a premalignant stage of NB during the fetal development and subsequent molecular alterations after birth, resulting in NBs that were phenotypically similar but genetically different.

  2. Cognitive impairments in patients with intractable temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Mahgol Tavakoli

    2011-01-01

    Conclusions: These findings indicated that WMS-III and WAIS-R can differentiate patients with refractory temporal lobe epilepsy from normal subjects. However, the obtained cognitive profile could not differentiate between the right and the left TLE.

  3. 3C 84 Expanding Radio Lobe Revealed by VSOP Observations

    Science.gov (United States)

    Asada, K.; Kameno, S.; Shen, Z.-Q.; Shinji, H.; Gabuzda, D. C.; Inoue, M.

    2009-08-01

    We report the detection of the expansion and inner proper motions of a young radio lobe associated with the bright radio source 3C 84 in the Seyfert galaxy NGC 1275 using multi-epoch VSOP observation. The observed inner proper motions are consistent with the evolution scenario of classical double radio sources. The apparent expansion velocity is 0.50 ± 0.09 c, and the age of radio lobe is estimated to be 45.7 ± 8.9 years in 2001. The total flux density at 5 GHz increased at the end of the 1950's, with several peaks in the middle of the 1980's, and is in a decay phase now. The decay of total flux density can be naturally explained by an adiabatic cooling due to the expansion of the radio lobe, and previously measured spectral indices suggest that the emission comes from the surface of the radio lobe.

  4. The right parietal lobe is critical for visual working memory.

    Science.gov (United States)

    Berryhill, Marian E; Olson, Ingrid R

    2008-01-01

    Visual working memory (VWM) permits the maintenance of object identities and their locations across brief delays such as those accompanying eye movements. Recent neuroimaging studies have emphasized the role of the posterior parietal lobe in this process although the specific nature of this involvement in VWM remains controversial. Neuroimaging findings suggest that the parietal lobe may have a general role in remembering various types of visual information whereas neuropsychological findings suggest that parietal involvement is primarily related to motor spatial attention and spatial memory. In the present study, patients with unilateral right parietal lobe damage, lacking symptoms of neglect, were tested in several VWM old/new recognition tasks. Parietal damage lead to impaired performance on all VWM tasks, including spatial, object, and object/spatial conjunction tasks. Deficits were found across several stimulus categories. These results provide neuropsychological support for neuroimaging results, and more generally indicate that the parietal lobe serves a general role in diverse forms of VWM.

  5. Impaired speech repetition and left parietal lobe damage

    National Research Council Canada - National Science Library

    Fridriksson, Julius; Kjartansson, Olafur; Morgan, Paul S; Hjaltason, Haukur; Magnusdottir, Sigridur; Bonilha, Leonardo; Rorden, Christopher

    2010-01-01

    .... However, perfusion-weighted MRI revealed that tissue dysfunction, in the form of either frank damage or hypoperfusion, to the left inferior parietal lobe, rather than the underlying white matter...

  6. Automated twin identification technique for use with electron backscatter diffraction.

    Energy Technology Data Exchange (ETDEWEB)

    Henrie, B. L. (Benjamin Lyman); Mason, T. A. (Thomas A.); Bingert, J. F. (John F.)

    2004-01-01

    Historically, twinning information has been obtained by optical microscopy, TEM, and neutron diffraction. Recent research has shown that automated electron backscatter diffraction (EBSD) can be used to extract reliable twinning statistics. An automated twin identification technique for use with EBSD has facilitated a greater understanding of deformation twinning in materials. The key features of this automated framework are the use of the crystallographic definition of twin relationships, the inclination of the common K, plane at a twin boundary, and the correct identification of the parent orientation in a parent/twin pair. The complex nature of the parent/twin interactions required the use of a voting scheme to correctly identify parent orientations. In those few cases were the voting scheme was unable to determine parent orientation (< 2 pct) the algorithm allows for manual selection. Twin area fractions are categorized by operative twin systems along with secondary and tertiary twinning. These statistics are reported for {alpha}-zirconium and 316L stainless steel. These improved twin statistics can help quantify deformation processes as well as provide validation of plasticity models for materials that exhibit deformation twinning.

  7. Topographic and Stochastic Influences on Pahoehoe Lava Lobe Emplacement

    Science.gov (United States)

    Hamilton, Christopher W.; Glaze, Lori S.; James, Mike R.; Baloga, Stephen M.

    2013-01-01

    A detailed understanding of pahoehoe emplacement is necessary for developing accurate models of flow field development, assessing hazards, and interpreting the significance of lava morphology on Earth and other planetary surfaces. Active pahoehoe lobes on Kilauea Volcano, Hawaii, were examined on 21-26 February 2006 using oblique time-series stereo-photogrammetry and differential global positioning system (DGPS) measurements. During this time, the local discharge rate for peripheral lava lobes was generally constant at 0.0061 +/- 0.0019 m3/s, but the areal coverage rate of the lobes exhibited a periodic increase every 4.13 +/- 0.64 minutes. This periodicity is attributed to the time required for the pressure within the liquid lava core to exceed the cooling induced strength of its margins. The pahoehoe flow advanced through a series of down slope and cross-slope breakouts, which began as approximately 0.2 m-thick units (i.e., toes) that coalesced and inflated to become approximately meter-thick lobes. The lobes were thickest above the lowest points of the initial topography and above shallow to reverse facing slopes, defined relative to the local flow direction. The flow path was typically controlled by high-standing topography, with the zone directly adjacent to the final lobe margin having an average relief that was a few centimeters higher than the lava inundated region. This suggests that toe-scale topography can, at least temporarily, exert strong controls on pahoehoe flow paths by impeding the lateral spreading of the lobe. Observed cycles of enhanced areal spreading and inflated lobe morphology are also explored using a model that considers the statistical likelihood of sequential breakouts from active flow margins and the effects of topographic barriers.

  8. Impact of Modal Parameters on Milling Process Chatter Stability Lobes

    Institute of Scientific and Technical Information of China (English)

    LI Zhongqun; LIU Qiang

    2006-01-01

    Modals of the machine/tool and machine/part system are the principal factors affecting the stability of a milling process. Based on the modeling of chatter stability of milling process, the influence of modal parameters on chatter stability lobes independently or jointly has been analyzed by simulation. Peak-to-valley specific value, lobe coefficient and the corresponding calculation formula have been put forward. General laws and steps of modal simplification for multimodality system have been summarized.

  9. The ‘when’ pathway of the right parietal lobe

    OpenAIRE

    Battelli, Lorella; Pascual-Leone, Alvaro; Cavanagh, Patrick

    2007-01-01

    The order of events, whether two events are seen as simultaneous or successive, sets the stage for the moment-to-moment interpretation of the visual world. Evidence from patients who have lesions to the parietal lobes and transcranial magnetic stimulation studies in normal subjects suggest that the right inferior parietal lobe underlies this analysis of event timing. Judgment of temporal order, simultaneity and high-level motion are all compromised following right parietal lesions and degrade...

  10. A volumetric study of parietal lobe subregions in Turner syndrome

    OpenAIRE

    Brown, Wendy E.; Shelli R Kesler; Eliez, Stephan; Warsofsky, Ilana S.; Haberecht, Michael; Reiss, Allan L.

    2004-01-01

    Turner syndrome, a genetic disorder that results from the complete or partial absence of an X chromosome in females, has been associated with specific impairment in visuospatial cognition. Previous studies have demonstrated a relationship between parietal lobe abnormalities and visuospatial deficits in Turner syndrome. We used high-resolution magnetic resonance imaging to measure parietal lobe subdivisions in 14 participants with Turner syndrome (mean age 13 years 5 months, SD 5 years) and 14...

  11. Characterization of Gastric Microbiota in Twins.

    Science.gov (United States)

    Dong, Quanjiang; Xin, Yongning; Wang, Lili; Meng, Xinying; Yu, Xinjuan; Lu, Linlin; Xuan, Shiying

    2017-02-01

    Contribution of host genetic backgrounds in the development of gastric microbiota has not been clearly defined. This study was aimed to characterize the biodiversity, structure and composition of gastric microbiota among twins. A total of four pairs of twins and eight unrelated individuals were enrolled in the study. Antral biopsies were obtained during endoscopy. The bacterial 16S rRNA gene was amplified and pyrosequenced. Sequences were analyzed for the composition, structure, and α and β diversities of gastric microbiota. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, and Fusobacteria were the most predominant phyla of gastric microbiota. Each individual, twins as well as unrelated individuals, harbored a microbiota of distinct composition. There was no evidence of additional similarity in the richness and evenness of gastric microbiota among co-twins as compared to unrelated individuals. Calculations of θYC and PCoA demonstrated that the structure similarity of gastric microbial community between co-twins did not increase compared to unrelated individuals. In contrast, the structure of microbiota was altered enormously by Helicobacter pylori infection. These results suggest that host genetic backgrounds had little effect in shaping the gastric microbiota. This property of gastric microbiota could facilitate the studies discerning the role of microbiota from genetic grounds in the pathogenesis.

  12. Coupling dynamic of twin supersonic jets

    Science.gov (United States)

    Kuo, Ching-Wen; Cluts, Jordan; Samimy, Mo

    2015-11-01

    In a supersonic shock-containing jet, the interaction of large-scale structures in the jet's shear layer with the shock waves generates acoustic waves. The waves propagate upstream, excite the jet initial shear layer instability, establish a feedback loop at certain conditions, and generate screech noise. The screech normally contains different modes of various strengths. Similarly, twin-jet plumes contain screech tones. If the dynamics of the two jet plumes are synchronized, the screech amplitude could be significantly amplified. There is a proposed analytical model in the literature for screech synchronization in twin rectangular jets. This model shows that with no phase difference in acoustic waves arriving at neighboring nozzle lips, twin-jet plumes feature a strong coupling with a significant level of screech tones. In this work the maximum nozzle separation distance for sustained screech synchronization and strong coupling is analytically derived. This model is used with our round twin-jet experiments and the predicted coupling level agrees well with the experimental results. Near-field microphone measurements and schlieren visualization along with the analytical model are used to investigate the coupling mechanisms of twin supersonic jets. Supported by ONR.

  13. On The Depolarization Asymmetry Seen in Giant Radio Lobes

    CERN Document Server

    Bell, M B

    2012-01-01

    The depolarization asymmetry seen in double-lobed radio sources, referred to as the Laing-Garrington (L-G) effect where more rapid depolarization is seen in the lobe with no visible jet as the wavelength increases, can be explained either by internal differences between the two lobes, or by an external Faraday screen that lies in front of only the depolarized lobe. If the jet one-sidedness is due to relativistic beaming the depolarization asymmetry must be due to an intervening Faraday screen. If it is intrinsic the depolarization asymmetry must be related to internal differences in the lobes. We assume in this paper that the speed in the outer jet of several Fanaroff-Riley Class 1 (FRI) sources exhibiting the L-G effect is close to the 0.1c reported by several other investigators. For these sources we find that the jet one-sidedness cannot be explained by beaming and therefore must be intrinsic. In these FRI sources the L-G effect must be due to differences that originate inside the lobes themselves. Althoug...

  14. Identifying the magnetotail lobes with Cluster magnetometer data

    Science.gov (United States)

    Coxon, J. C.; Jackman, C. M.; Freeman, M. P.; Forsyth, C.; Rae, I. J.

    2016-02-01

    We describe a novel method for identifying times when a spacecraft is in Earth's magnetotail lobes solely using magnetometer data. We propose that lobe intervals can be well identified as times when the magnetic field is strong and relatively invariant, defined using thresholds in the magnitude of BX and the standard deviation σ of the magnetic field magnitude. Using data from the Cluster spacecraft at downtail distances greater than 8 RE during 2001-2009, we find that thresholds of 30 nT and 3.5 nT, respectively, optimize agreement with a previous, independently derived lobe identification method that used both magnetic and plasma data over the same interval. Specifically, our method has a moderately high accuracy (66%) and a low probability of false detection (11%) in comparison to the other method. Furthermore, our method identifies the lobe on many other occasions when the previous method was unable to make any identification and yields longer continuous intervals in the lobe than the previous method, with intervals at the 90th percentile being triple the length. Our method also allows for analyses of the lobes outside the time span of the previous method.

  15. Medical image of the week: right middle lobe syndrome

    Directory of Open Access Journals (Sweden)

    Cristan EA

    2016-05-01

    Full Text Available No abstract available. Article truncated at 150 words. A 73 year-old woman, a lifetime non-smoker, presented to the pulmonary clinic with chronic dyspnea on exertion and cough. Physical exam was unremarkable and pulmonary function testing showed normal spirometry. A chest radiograph revealed calcified mediastinal adenopathy and increased density in the right middle lobe region (Figure 1. A computed tomography scan of the chest revealed significant narrowing of the right middle lobe bronchus with partial atelectasis and prominent calcified mediastinal lymphadenopathy (Figure 2. Bronchoscopy showed no endobronchial lesions but there was evidence of extrinsic compression surrounding the right middle lobe orifice. An endobronchial biopsy revealed noncaseating granulomas. Bronchoscopy cultures and cytology were negative and this was presumed to be from a previous infection with histoplasmosis given the patient’s long-term residence in an endemic area. Given chronic narrowing of right middle lobe bronchus with persistent atelectasis of the right middle lobe, the patient was diagnosed with right middle lobe syndrome. ...

  16. Near-death experiences and the temporal lobe.

    Science.gov (United States)

    Britton, Willoughby B; Bootzin, Richard R

    2004-04-01

    Many studies in humans suggest that altered temporal lobe functioning, especially functioning in the right temporal lobe, is involved in mystical and religious experiences. We investigated temporal lobe functioning in individuals who reported having transcendental "near-death experiences" during life-threatening events. These individuals were found to have more temporal lobe epileptiform electroencephalographic activity than control subjects and also reported significantly more temporal lobe epileptic symptoms. Contrary to predictions, epileptiform activity was nearly completely lateralized to the left hemisphere. The near-death experience was not associated with dysfunctional stress reactions such as dissociation, posttraumatic stress disorder, and substance abuse, but rather was associated with positive coping styles. Additional analyses revealed that near-death experiencers had altered sleep patterns, specifically, a shorter duration of sleep and delayed REM sleep relative to the control group. These results suggest that altered temporal lobe functioning may be involved in the near-death experience and that individuals who have had such experiences are physiologically distinct from the general population.

  17. Famous People Knowledge and the Right and Left Temporal Lobes

    Science.gov (United States)

    Snowden, Julie S.; Thompson, Jennifer C.; Neary, David

    2012-01-01

    It is generally accepted that the anterior temporal lobes support knowledge of famous people. The specific roles of the right and left temporal lobe remain a subject of debate, with some studies suggesting differential roles based on modality (visual versus verbal information) and others category (person knowledge versus general semantics). The present study re-examined performance of semantic dementia patients with predominantly right and predominantly left temporal lobe atrophy on famous face, famous name and general semantic tasks, with the specific aim of testing the hypothesis that the right temporal lobe has a privileged role for person knowledge and the left temporal lobe for general semantic knowledge. Comparisons of performance rankings across tasks showed no evidence to support this hypothesis. By contrast, there was robust evidence from naming, identification and familiarity measures for modality effects: right-sided atrophy being associated with relatively greater impairment for faces and visual tasks and left-sided atrophy for names and verbal tasks. A double dissociation in test scores in two patients reinforced these findings. The data present a challenge for the influential ‘semantic hub’ model, which views the anterior temporal lobes as an area of convergence in which semantic information is represented in amodal form. PMID:22207421

  18. Sex differences in parietal lobe structure and development.

    Science.gov (United States)

    Salinas, Joel; Mills, Elizabeth D; Conrad, Amy L; Koscik, Timothy; Andreasen, Nancy C; Nopoulos, Peg

    2012-02-01

    Structural magnetic resonance imaging studies provide evidence for sex differences in the human brain. Differences in surface area and the proportion of gray to white matter volume are observed, in particular in the parietal lobe. To our knowledge, no studies have examined sex differences in parietal lobe structure in younger populations or in the context of development. The present study evaluated sex differences in the structure of the parietal lobe in children aged 7 to 17 years. In addition, by adding a cohort of previously studied adults aged 18 to 50 years, sex differences in parietal lobe structure were examined across the age span of 7 to 50 years. Compared with the adult sample, the younger sample showed that the ratio of parietal lobe cortex to white matter was greater in female brains, but no sex differences in surface area. When examining the effects of age, surface area exhibited a significant sex-age interaction. In male brains, there was essentially no decrease in surfaces area over time, whereas in female brains, there was a significant decrease in surface area over time. These findings support the notion of structural sex differences in the parietal lobe, not only in the context of cross-sectional assessment but also in terms of differences in developmental trajectories. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

  19. Bicavitary effusion secondary to liver lobe torsion in a dog

    Directory of Open Access Journals (Sweden)

    Khan Z

    2016-04-01

    Full Text Available Zaheda Khan,1 Kathryn Gates,2 Stephen A Simpson,31Emergency and Critical Care, Animal Specialty and Emergency Center, Los Angeles, CA, 2Emergency and Critical Care, Advanced Critical Care, Emergency and Specialty Services, Culver City, CA 3Emergency and Critical Care, Southern California Veterinary Specialty Hospital, Irvine, CA, USA Abstract: We described the diagnosis and successful treatment of pleural and peritoneal effusion secondary to liver lobe torsion in a dog. A 12-year-old female spayed Borzoi dog was referred for heart failure. Emergency room thoracic and abdominal ultrasound showed a large volume of pleural effusion with mild peritoneal effusion and an abdominal mass. Pleural fluid analysis classified the effusion as exudative. A complete ultrasound revealed mild peritoneal effusion and decreased blood flow to the right liver lobe. Other causes of bicavitary effusion were ruled out based on blood work, ultrasound, echocardiogram, and computed tomography. The patient was taken to surgery and diagnosed with caudate liver lobe torsion and had a liver lobectomy. At the 2-week postoperative recheck, the patient was doing well and there was complete resolution of the pleural effusion. Liver lobe torsion is a rare occurrence in dogs and can be difficult to diagnose. Clinical signs are nonspecific for liver lobe torsion and patients may present in respiratory distress with significant pleural fluid accumulation. When assessing patients with pleural and peritoneal effusion, liver lobe torsion should be considered as a differential diagnosis.Keywords: pleural effusion, peritoneal effusion, hepatic torsion

  20. Physiopathogenetic Interrelationship between Nocturnal Frontal Lobe Epilepsy and NREM Arousal Parasomnias

    Science.gov (United States)

    Halász, Péter; Kelemen, Anna; Szűcs, Anna

    2012-01-01

    Aims. To build up a coherent shared pathophysiology of NFLE and AP and discuss the underlying functional network. Methods. Reviewing relevant published data we point out common features in semiology of events, relations to macro- and microstructural dynamism of NREM sleep, to cholinergic arousal mechanism and genetic aspects. Results. We propose that pathological arousals accompanied by confused behavior with autonomic signs and/or hypermotor automatisms are expressions of the frontal cholinergic arousal function of different degree, during the condition of depressed cognition by frontodorsal functional loss in NREM sleep. This may happen either if the frontal cortical Ach receptors are mutated in ADNFLE (and probably also in genetically not proved nonlesional cases as well), or without epileptic disorder, in AP, assuming gain in receptor functions in both conditions. This hypothesis incorporates the previous “liberation theory” of Tassinari and the “state dissociation hypothesis” of Bassetti and Terzaghi). We propose that NFLE and IGE represent epileptic disorders of the two antagonistic twin systems in the frontal lobe. NFLE is the epileptic facilitation of the ergotropic frontal arousal system whereas absence epilepsy is the epileptic facilitation of burst-firing working mode of the spindle and delta producing frontal thalamocortical throphotropic sleep system. Significance. The proposed physiopathogenesis conceptualize epilepsies in physiologically meaningful networks. PMID:22953061

  1. Near-field and far-field engineering of semiconductor lasers

    Science.gov (United States)

    Yu, Nanfang

    Plasmonics focuses on the interaction between light and metallic films or nanostructures. In the last two decades, intensive research efforts were devoted to exploring the extremely broad applications of plasmonics. My research combines the versatility of plasmonics with active light sources, i.e., quantum cascade lasers (QCLs). This thesis focuses on the application of plasmonics in near-field and far-field engineering of semiconductor lasers, specifically, subwavelength focusing in the near-field, and laser beam collimation and polarization control. The first chapter of this thesis lays out fundamental materials necessary for understanding the following chapters. Systematic simulation and experimental results are presented in Chapter 2 to demonstrate that the integration of a suitably designed one dimensional or two dimensional plasmonic structures on the facet of QCLs can reduce the beam divergence by more than one order of magnitude. The devices with optimized collimators preserve a high output power, comparable to that of the unpatterned lasers. Chapter 3 demonstrates that the polarization state of the output of semiconductor lasers can be controlled by defining plasmonic structures on the laser facet. An integrated plasmonic polarizer can project the polarization of a semiconductor laser onto other directions. By patterning a facet with two orthogonal grating-aperture structures, a QCL can produce emission consisting of a superposition of a linearly and right-circularly polarized light, a first step towards a circularly-polarized laser. Chapter 4 presents experimental work on the coupled-rod antennas and the bowtie antennas patterned on the facet of QCLs. Both designs can provide an optical field confinement on the order of lambda/50 and with peak intensity on the order of 1 GW/cm2 in the antenna gap. The bowtie devices are more advanced due to better confinement of light into a single spot. Chapter 5 and 6 discuss two side research topics. Chapter 5

  2. Astronaut Twins Give Clues to Health Hazards of Spaceflight

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163391.html Astronaut Twins Give Clues to Health Hazards of Spaceflight NASA ... aboard the International Space Station, and his identical twin Mark, a retired astronaut. Mark remained on Earth ...

  3. Heritability of eleven metabolic phenotypes in Danish and Chinese twins

    DEFF Research Database (Denmark)

    Li, Shuxia; Duan, Hongmei; Pang, Zengchang

    2013-01-01

    A twin-based comparative study on the genetic influences in metabolic endophenotypes in two populations of substantial ethnic, environmental, and cultural differences was performed. Design and Methods: Data on 11 metabolic phenotypes including anthropometric measures, blood glucose, and lipids...... levels as well as blood pressure were available from 756 pairs of Danish twins (309 monozygotic and 447 dizygotic twin pairs) with a mean age of 38 years (range: 18-67) and from 325 pairs of Chinese twins (183 monozygotic and 142 dizygotic twin pairs) with a mean age of 40.5 years (range: 18-69). Twin...... similar heritability patterns in the two samples with body weight showing only a slight difference. Higher genetic influences were estimated for fasting blood glucose level in Chinese twins, whereas the Danish twins showed more genetic regulation over most lipids phenotypes. Systolic blood pressure...

  4. TWIN BIRTHS IN THE COMOROS MA ABDUL ABSTRACT Objective

    African Journals Online (AJOL)

    hi-tech

    2000-11-11

    Nov 11, 2000 ... Conclusion: Multiple pregnancy is common in the Comoros and the epidemiology and ... Of the 23 twin deliveries in Domoni, only one neonate. (a second twin) had ... including ambiguous genitalia and died in the immediate.

  5. Profile of asymmetrical retinopathy of prematurity in twins

    Directory of Open Access Journals (Sweden)

    Azad Rajvardhan

    2010-01-01

    Full Text Available Background: In twin births, both babies have the same gestational age and pre-natal conditions. However, twins may develop a varied retinopathy of prematurity (ROP course depending on birth weight and other systemic factors. Objective: To study the profile of asymmetric ROP in twins Design: Retrospective study Setting: Tertiary ROP referral eye hospital. Materials and Methods: The profile of 56 pairs of twins with ROP were studied and analyzed for differences in zone or need for treatment, while studying possible causes for the varied outcome. Results: In 45 pairs of twins (80% the disease progressed identically in both eyes, while in 11 pairs (20% the ROP showed differences in zone or need for treatment. Four of these pairs were discordant. In 3 of these 4 pairs, the heavier birth weight twin had a more severe ROP course. Conclusions: Twins can present with asymmetric ROP course, and it is therefore essential to examine both twins as per screening protocols.

  6. A Twin Protection Effect? Explaining Twin Survival Advantages with a Two-Process Mortality Model.

    Science.gov (United States)

    Sharrow, David J; Anderson, James J

    2016-01-01

    Twin studies that focus on the correlation in age-at-death between twin pairs have yielded important insights into the heritability and role of genetic factors in determining lifespan, but less attention is paid to the biological and social role of zygosity itself in determining survival across the entire life course. Using data from the Danish Twin Registry and the Human Mortality Database, we show that monozygotic twins have greater cumulative survival proportions at nearly every age compared to dizygotic twins and the Danish general population. We examine this survival advantage by fitting these data with a two-process mortality model that partitions survivorship patterns into extrinsic and intrinsic mortality processes roughly corresponding to acute, environmental and chronic, biological origins. We find intrinsic processes confer a survival advantage at older ages for males, while at younger ages, all monozygotic twins show a health protection effect against extrinsic death akin to a marriage protection effect. While existing research suggests an increasingly important role for genetic factors at very advanced ages, we conclude that the social closeness of monozygotic twins is a plausible driver of the survival advantage at ages <65.

  7. Time, Topology and the Twin Paradox

    CERN Document Server

    Luminet, J -P

    2009-01-01

    The twin paradox is the best known thought experiment associated with Einstein's theory of relativity. An astronaut who makes a journey into space in a high-speed rocket will return home to find he has aged less than a twin who stayed on Earth. This result appears puzzling, since the situation seems symmetrical, as the homebody twin can be considered to have done the travelling with respect to the traveller. Hence it is called a "paradox". In fact, there is no contradiction and the apparent paradox has a simple resolution in Special Relativity with infinite flat space. In General Relativity (dealing with gravitational fields and curved space-time), or in a compact space such as the hypersphere or a multiply connected finite space, the paradox is more complicated, but its resolution provides new insights about the structure of spacetime and the limitations of the equivalence between inertial reference frames.

  8. Aging and communication in the twin paradox

    Science.gov (United States)

    de Wolf, David A.

    2016-11-01

    The twin paradox of the special theory of relativity has given rize to a large body of literature discussing its implications. In its standard form, the traveler changes velocity only at the destination of the trip, so that he appears to perceive an improbably instantaneous and non-continuous change in age of the stationary twin. In this work, a smooth velocity/acceleration profile is used that allows the abrupt velocity-change case as a limit. All gravitational effects are ignored in this treatment. Aside from mutual perception of simultaneous clock times in an accelerating frame, constant communication of clock times between the twins by means of (digital) light signals is shown to be possible, in principle if not in practice.

  9. Plasmonic twinned silver nanoparticles with molecular precision

    Science.gov (United States)

    Yang, Huayan; Wang, Yu; Chen, Xi; Zhao, Xiaojing; Gu, Lin; Huang, Huaqi; Yan, Juanzhu; Xu, Chaofa; Li, Gang; Wu, Junchao; Edwards, Alison J.; Dittrich, Birger; Tang, Zichao; Wang, Dongdong; Lehtovaara, Lauri; Häkkinen, Hannu; Zheng, Nanfeng

    2016-09-01

    Determining the structures of nanoparticles at atomic resolution is vital to understand their structure-property correlations. Large metal nanoparticles with core diameter beyond 2 nm have, to date, eluded characterization by single-crystal X-ray analysis. Here we report the chemical syntheses and structures of two giant thiolated Ag nanoparticles containing 136 and 374 Ag atoms (that is, up to 3 nm core diameter). As the largest thiolated metal nanoparticles crystallographically determined so far, these Ag nanoparticles enter the truly metallic regime with the emergence of surface plasmon resonance. As miniatures of fivefold twinned nanostructures, these structures demonstrate a subtle distortion within fivefold twinned nanostructures of face-centred cubic metals. The Ag nanoparticles reported in this work serve as excellent models to understand the detailed structure distortion within twinned metal nanostructures and also how silver nanoparticles can span from the molecular to the metallic regime.

  10. Aging and communication in the twin paradox

    CERN Document Server

    de Wolf, David A

    2016-01-01

    The twin paradox of the special theory of relativity has given rise to a large body of literature discussing its implications. In its standard form, the traveler changes velocity only at the destination of the trip, so that he appears to perceive an improbably instantaneous and non-continuous change in age of the stationary twin. In this work, a smooth velocity/acceleration profile is used that allows the abrupt velocity-change case as a limit. All gravitational effects are ignored in this treatment. Aside from mutual perception of simultaneous clock times in an accelerating frame, constant communication of clock times between the twins by means of (digital) light signals is shown to be possible, in principle if not in practice.

  11. Solar twins in the ELODIE archive

    CERN Document Server

    Mahdi, Dhiaa; Blanco-Cuaresma, Sergi; Chemin, Laurent

    2016-01-01

    A large dataset of ~2800 spectra extracted from the ELODIE archive was analysed in order to find solar twins. A list of stellar spectra closely resembling the spectrum of the Sun was selected by applying a purely differential method, directly on the fluxes. As solar reference, 18 spectra of asteroids, Moon and blue sky were used. Atmospheric parameters and differential abundances of 8 chemical elements were determined for the solar twin candidates, after a careful selection of appropriate lines. The Li feature of the targets was investigated and additional information on absolute magnitude and age was gathered from the literature. HIP076114 (HD138573) is our best twin candidate, looking exactly like the Sun in all these properties.

  12. Prevention of preterm delivery in twin pregnancy

    DEFF Research Database (Denmark)

    Rode, Line; Tabor, Ann

    2014-01-01

    The incidence of twin gestation has increased markedly over the past decades, mostly because of increased use of assisted reproductive technologies. Twin pregnancies are at increased risk of preterm delivery (i.e. birth before 37 weeks of gestation). Multiple gestations therefore account for 2......-3% of all pregnancies but constitute at least 10% of cases of preterm delivery. Complications from preterm birth are not limited to the neonatal period, such as in retinopathy of prematurity, intraventricular haemorrhage, necrotising enterocolitis, respiratory disorder and sepsis; they can also constitute......, it is mandatory to evaluate the proposed treatments in randomised trials of multiple gestations. In this chapter, we describe the results of trials to prevent preterm delivery in twin pregnancies....

  13. Infant mortality in twin pregnancies following in-utero demise of the co-twin

    Institute of Scientific and Technical Information of China (English)

    Boubakari Ibrahimou; Hamisu M Salihu; Muktar H Aliyu; Gary English; Getachew Dagne

    2015-01-01

    Objective:To assess whether conversion from twin to singleton pregnancy following the demise of a co-twin influences survival.Methods:This retrospective study compared the risk for neonatal, post-neonatal and infant death for converted co-twins versus unconverted co-twins using the US matched multiple file dataset for the period 1995-2000. We also examined the same risks for converted versus same-quantile co-twins, hazard ratios (HR) and 95% confidence intervals (CI) were computed using Cox Proportional Hazards models.Results:The risk for neonatal (HR=0.18, 95%CI: 0.09-0.34 andHR=0.69, 95%CI: 0.50- 0.96) and infant death (HR=0.22, 95%CI: 0.12-0.42 andHR=0.57, 95%CI: 0.42-0.77) were significantly lower for converted twins than for unconverted twins and same-quantile twins, respectively. For black compared to white, the risk for post-neonatal death increased by 89% (HR=1.89, 95%CI= 1.03, 3.48), and 79% (HR=1.79, 95%CI=1.53, 2.09) for convertedvs. unconverted and convertedvs. same-quantile, respectively. For converted black, the risk for neonatal death decreased by 17% (HR=0.83, 95%CI=0.73-0.93) as compared to unconverted.Conclusions: Risks for all mortality types were lower among converted co-twins than their unconverted or same-quantile counterparts. The lower neonatal and higher post-neonatal mortality among black require future research.

  14. Determination of femtosecond-laser-induced refractive-index changes in an optical fiber from far-field measurements.

    Science.gov (United States)

    Savolainen, Juha-Matti; Grüner-Nielsen, Lars; Kristensen, Poul; Balling, Peter

    2014-06-15

    A new method for direct writing of localized, circularly symmetric refractive-index changes in optical fibers with a femtosecond laser is demonstrated. The refractive-index changes are characterized using a novel approach employing comparison of numerical simulations to the measured far-field profiles of unmodified and modified fibers. From the analysis, a negative refractive-index change of -0.015±0.005 within a radius of (0.6±0.1)  μm is determined.

  15. Benchmark Modeling of the Near-Field and Far-Field Wave Effects of Wave Energy Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rhinefrank, Kenneth E; Haller, Merrick C; Ozkan-Haller, H Tuba

    2013-01-26

    This project is an industry-led partnership between Columbia Power Technologies and Oregon State University that will perform benchmark laboratory experiments and numerical modeling of the near-field and far-field impacts of wave scattering from an array of wave energy devices. These benchmark experimental observations will help to fill a gaping hole in our present knowledge of the near-field effects of multiple, floating wave energy converters and are a critical requirement for estimating the potential far-field environmental effects of wave energy arrays. The experiments will be performed at the Hinsdale Wave Research Laboratory (Oregon State University) and will utilize an array of newly developed Buoys' that are realistic, lab-scale floating power converters. The array of Buoys will be subjected to realistic, directional wave forcing (1:33 scale) that will approximate the expected conditions (waves and water depths) to be found off the Central Oregon Coast. Experimental observations will include comprehensive in-situ wave and current measurements as well as a suite of novel optical measurements. These new optical capabilities will include imaging of the 3D wave scattering using a binocular stereo camera system, as well as 3D device motion tracking using a newly acquired LED system. These observing systems will capture the 3D motion history of individual Buoys as well as resolve the 3D scattered wave field; thus resolving the constructive and destructive wave interference patterns produced by the array at high resolution. These data combined with the device motion tracking will provide necessary information for array design in order to balance array performance with the mitigation of far-field impacts. As a benchmark data set, these data will be an important resource for testing of models for wave/buoy interactions, buoy performance, and far-field effects on wave and current patterns due to the presence of arrays. Under the proposed project we will initiate

  16. Towards an optical far-field measurement of higher-order multipole contributions to the scattering response of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Thomas; Orlov, Sergej [Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1/Bldg. 24, 91058 Erlangen (Germany); Institute of Optics, Information and Photonics, University Erlangen-Nuremberg, Staudtstr. 7/B2, 91058 Erlangen (Germany); Leuchs, Gerd; Banzer, Peter, E-mail: peter.banzer@mpl.mpg.de [Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1/Bldg. 24, 91058 Erlangen (Germany); Institute of Optics, Information and Photonics, University Erlangen-Nuremberg, Staudtstr. 7/B2, 91058 Erlangen (Germany); Department of Physics, University of Ottawa, 25 Templeton St., Ottawa, Ontario K1N 6N5 (Canada)

    2015-03-02

    We experimentally show an all-optical multipolar decomposition of the lowest-order eigenmodes of a single gold nanoprism using azimuthally and radially polarized cylindrical vector beams. By scanning the particle through these tailored field distributions, the multipolar character of the eigenmodes gets encoded into 2D-scanning intensity maps even for higher-order contributions to the eigenmode that are too weak to be discerned in the direct far-field scattering response. This method enables a detailed optical mode analysis of individual nanoparticles.

  17. Towards an optical far-field measurement of higher-order multipole contributions to the scattering response of nanoparticles

    CERN Document Server

    Bauer, Thomas; Leuchs, Gerd; Banzer, Peter

    2014-01-01

    We experimentally show an all-optical multipolar decomposition of the lowest-order Eigenmodes of a single gold nanoprism using azimuthally and radially polarized cylindrical vector beams. By scanning the particle through these tailored field distributions, the multipolar character of the Eigenmodes gets encoded into 2D-scanning intensity maps even for higher-order contributions to the Eigenmode that are too weak to be discerned in the direct far-field scattering response. This method enables a detailed optical mode analysis of individual nanoparticles.

  18. Social Determinants of Smoking Behavior: The Healthy Twin Study, Korea

    OpenAIRE

    Kim, Youn Sik; Ko, Hansoo; Yoon, Changgyo; Lee, Dong-Hun; Sung, Joohon

    2012-01-01

    Objectives The purpose of this study was to identify any influence of socioeconomic status on smoking and smoking cessation in a situation where genetic factors are controlled. Methods The sample for this study was 2502 members of the twins and families cohort who participated in the Korean Healthy Twins Study from 2005 to 2009. Groups of brothers or sisters, including twins and fraternal twins, were compared in terms of smoking and smoking cessation behaviors according to differences in soci...

  19. Dichorionic Diamniotic Twin Pregnancy Discordant for Bladder Exstrophy

    OpenAIRE

    William Tu; Jane Chueh; William Kennedy

    2009-01-01

    A 38 year-old woman presented with a dichorionic diamniotic twin pregnancy at gestational age of 32 weeks concerning for an abdominal wall mass in one of the twins. Initial ultrasound evaluation was suspicious for an omphalocele, but the affected twin was found to have bladder exstrophy at birth. This illustrates the difficulties of accurate prenatal diagnosis of bladder exstrophy in a twin pregnancy at a late gestation.

  20. Dichorionic Diamniotic Twin Pregnancy Discordant for Bladder Exstrophy

    Directory of Open Access Journals (Sweden)

    William Tu

    2009-01-01

    Full Text Available A 38 year-old woman presented with a dichorionic diamniotic twin pregnancy at gestational age of 32 weeks concerning for an abdominal wall mass in one of the twins. Initial ultrasound evaluation was suspicious for an omphalocele, but the affected twin was found to have bladder exstrophy at birth. This illustrates the difficulties of accurate prenatal diagnosis of bladder exstrophy in a twin pregnancy at a late gestation.