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Mirror Image (mirror + image)

Distribution by Scientific Domains

Chemistry	27%
Medical Sciences	22%
Life Sciences	11%
Humanities and Social Sciences	11%

Selected Abstracts

Mirror image left-sided gastroschisis

ANZ JOURNAL OF SURGERY, Issue 6 2010
Ramnik Patel FRCSEd
No abstract is available for this article. [source]

Ictal Brain Hyperperfusion Contralateral to Seizure Onset: The SPECT Mirror Image

EPILEPSIA, Issue 1 2006
Gilles Huberfeld
Summary:,Purpose: Ictal single-photon emission computed tomography (SPECT) may help localize the seizure-onset zone (SOZ) by detecting changes in regional cerebral blood flow induced by epileptic discharges. This imaging method also reveals hyperperfusions in areas of seizure propagation, including the hemisphere contralateral to the SOZ. We have studied the occurrence, the topography, and the clinical value of such contralateral ictal hyperperfusion areas (HPAs). Methods: We examined data from presurgical evaluations of 36 consecutive patients with pharmacoresistant partial epilepsy of various localizations. Ictal and interictal SPECT examinations were made with 99mTc-ECD, and the scans were processed for coregistration, normalization, subtraction, and merging with MRI images. Results: Contralateral HPAs were observed in 72% of the patients: 50% of mesiotemporal epilepsy cases with hippocampal sclerosis, 85.7% of the other mesiotemporal epilepsies, 85.7% of neocortical lateral temporal epilepsies, and 87.5% of extratemporal epilepsies. Contralateral HPAs were usually symmetrical to the SOZ, forming a mirror image, observed in 57.1% of the patients. They could be slightly asymmetrical in mesiotemporal epilepsies, perhaps because of the particular anatomic pathways linking temporal lobes. In neocortical epilepsies, they were located in the cortex homotopic to the SOZ. Conclusions: We show that the symmetrical nature of the mirror image usually does not disturb SPECT interpretation. It can confirm the location of the SOZ (11 patients) and even occasionally improve the precision of its definition (nine patients) by restraining several potential SOZ-related HPAs to a single one or by permitting a restricted localization of the SOZ in a large HPA. [source]

Eastern European Attitudes to Integration with Western Europe

JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 2 2004
Anetta Caplanova
This article examines attitudes to membership of the EU and Nato amongst countries in central and eastern Europe. Sample survey data are obtained from the Eurobarometer surveys of transition and EU candidate countries. The empirical results suggest that support for membership increases with socio-economic variables such as in come and education, reflecting self-interest. But attitudinal variables are also important and, in particular, confidence in the free market economy impacts positively on support for membership. Support for EU membership is not a mirror image of that for Nato, with the differences appearing to revolve around self-interest. [source]

Enamel matrix derivative and titanium implants

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2003
An experimental pilot study in the rabbit
Aim: The aim of present study was to evaluate if an enamel matrix derivative (Emdogain®) may enhance bone formation and osseointegration of titanium implants, using a well-documented rabbit model. Material and methods: Thirty-six threaded commercially pure titanium (cp.ti.) implants were inserted in six New Zealand white rabbits. One implant was placed in each femur and two in each tibia. Prior to implant insertion approximately 0.5 mL of Emdogain (EMD) (test) or the vehicle gel (PGA: propylene glycol alginate) (control) was injected into the surgically prepared implant site. The follow-up time was 6 weeks. Biomechanical evaluations by resonance frequency analysis (RFA) and removal torque measurements (RTQ) were performed. Histomorphometrical quantifications were made on ground sections by measurements of the percentage of bone-to-metal contact, bone area inside the threads as well as outside the threads (mirror image). Bone lengths along the implant surface were also measured and used for shear strength calculations. Results: The results demonstrated no beneficial effects from the EMD treatment on bone formation around titanium implants in any of the tested parameters. Significant differences were demonstrated with removal torque test and shear force calculations for the control implants. No other parameter demonstrated a statistically significant difference. Conclusion: The results of the present study may indicate that EMD does not contribute to bone formation around titanium implants. This observation may indicate that the bone formation that occurs after EMD treatment in periodontal defects is the result of functional adaptation. However, further research is required to evaluate the effect of EMD treatment on bone formation. Zusammenfassung Schmelzmatrixprotein und Titanimplantate. Eine experimentelle Pilotstudie beim Kaninchen Zielsetzung: Untersuchung im gut dokumentierten Kaninchenmodell, ob Schmelzmatrixprotein (Emdogain®) die Knochenbildung und Osseointegration von Titanimplantaten verbessert. Material und Methoden: 36 kommerziell erhältliche Schraubenimplantate aus reinem Titan (cp.ti.) wurden bei 6 weißen Neuseeländischen Kaninchen inseriert. Ein Implantat wurde in jeden Femur und 2 in jede Tibia gesetzt. Vor Implantatinsertion wurden etwa 0,5 ml Emdogain (EMD) (Test) oder das Trägergel (PGA: Propylenglykolalginat) (Kontrolle) in die chirurgisch vorbereitete Insertionsstelle gespritzt. Die Nachuntersuchungszeit betrug 6 Wochen. Die biomechanischen Untersuchungen umfassten eine Resonanzfrequenzanalyse (RFA) und die Messung des Drehmoments, das zur Entfernung der Implantate nötig war (RTQ). Folgende histomorphometrische Messungen wurden auf Schliffpräparaten durchgeführt: Messung des prozentualen Knochen-zu-Metall-Kontaktes, Knochenbereich innerhalb und außerhalb der Schraubengewinde (Spiegelbild). Die Knochenlänge entlang der Implantate wurde ausgemessen und für Scherkraftberechnungen genutzt. Ergebnisse: Es konnten für keinen der untersuchten Parameter günstige Auswirkungen der Anwendung von EMD auf die Knochenbildung um Titanimplantate beobachtet werden. Signifikante Unterschiede konnten für RTQ und Scherkraftberechnungen für die Kontrollimplantate gezeigt werden. Für keinen anderen Parameter konnten statistisch signifikante Unterschiede gefunden werden. Schlussfolgerungen: Die Ergebnisse dieser Studie zeigen, dass der Einsatz von EMD nicht zur Knochenbildung um Titanimplantate beiträgt. Diese Beobachtung kann darauf hinweisen, dass die Knochenbildung, die nach Gabe von EMD in parodontalen Defekten stattfindet, das Ergebnis funktioneller Adaptation ist. Allerdings sind weitere Untersuchungen erforderlich, um die Auswirkung von EMD auf die Knochenbildung zu verstehen. Résumé Dérivés de la matrice amellaire et implants en titane. Une étude pilote expérimentale sur le lapin. But: Le but de cette étude était d'évaluer si un dérivé de la matrice amellaire (Emdogain®) pouvait augmenter la formation osseuse et l'ostéo-intégration d'implants en titane en utilisant un modèle éprouvé de lapin. Matériel et méthodes: 36 implants en titane commercialement purs (cp.ti.) ont été vissés chez 6 lapins blancs de Nouvelle Zélande. 1 implant fut placé dans chaque fémur et 2 dans chaque tibia. Préalablement à l'insertion, environ 0.5 mL d' Emdogain (EMD) (test) ou du gel vecteur (PGA: propylene glycol alginate) (control) fut injecté dans le site implantaire préparé chirurgicalement. Le suivi était réalisé sur 6 semaines. Des évaluations biomécaniques par analyse de la fréquence de résonance (RFA) et des mesures de torque de retrait (RTQ) furent utilisées. Les quantifications histo-morphométriques furent réalisées sur des coupes en mesurant le pourcentage de contact os-métal, les surfaces osseuses à l'intérieur ainsi qu'à l'extérieur des spires (Image miroir). Les longueurs d'os le long des surfaces implantaires furent aussi mesurées et utilisées pour calculer les forces de cisaillement. Résultats: Les résultats n'ont montré aucun effet bénéfique du traitement à l'EMD sur la formation osseuse autour des implants en titane pour aucun des paramètres test. De significatives différences furent trouvées avec le test de torque et les calculs de force de cisaillement pour les implants contrôles. Aucun autre paramètre ne montrait de différences statistiquement significatives. Conclusion: Les résultats de cette étude pourrait indiquer que l'EMD ne contribue pas à la formation osseuse autour des implants en titane. Cette observation peut indiquer que la formation osseuse qui survient après traitement à l'EMD dans les lésions parodontales serait le résultat d'une adaptation fonctionnelle. Cependant, de futures recherches sont nécessaires pour évaluer l'effet du traitement à l'EMD sur la formation osseuse. [source]

Cognitive Mapping as an Emergency Management Training Exercise

JOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 4 2004
David E. Alexander
This paper describes a scenario-based, table-top exercise which was given to a variety of postgraduate university classes in emergency preparedness and to some groups of trainee disaster managers. Participants in the exercise were asked to draw maps of a developing crisis situation and suggest a set of tactics for managing it. The results were analysed using theories of cognitive mapping. They showed that seven distinct kinds of map emerged from the sample of 67 collected. These were labelled well-defined, systematic, emblematic, ill-defined (cryptic), compressed, diagrammatic (ideographic) and mirror image. About 60 per cent of the maps depicted the majority of the elements, while the remaining 40 per cent were lacking in detail to varying degrees. The cognitive maps therefore introduced distortions into the representation of elements, and these were negatively correlated with the abilities, experience, knowledge and training of their authors, as manifested by their other work in the classroom. The extraordinary variety of perceptions of space and place during emergencies has considerable implications for how such events are managed during the crisis phase. [source]

Principal component analysis of landmarks from reversible images

JOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 1 2004
C. M. Theobald
Summary., We consider the use of principal component analysis to summarize the variation in labelled landmark data for images which are reversible in the sense that a mirror image may be defined for each image and the original and mirror images may be regarded as equally representative of the population. We examine the effect of including the original and mirror images on a principal component analysis based on the landmark co-ordinates. The inclusion of mirror images is found to lead to a simplified interpretation in which some components measure asymmetry in the images and the remainder depend symmetrically on pairs of co-ordinates. This is illustrated on shape variation in carrots. A second application is to the segmentation of X-ray computed tomography images of sheep to locate the inner boundary of the carcass. It is found that image boundaries can be identified more accurately by modelling them with principal components, and that including mirror images can offer a further improvement in accuracy. Similar arguments apply when a population of images is thought to be invariant under a rotation and may also be relevant when a principal component analysis is applied to descriptive statistics such as Fourier sums. [source]

The determination of planetary structure in tidally relaxed inclined systems

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2010
Rosemary A. Mardling
ABSTRACT The recent discovery of a transiting short-period planet on a slightly non-circular orbit with a massive highly eccentric companion orbiting the star HAT-P-13 offers the possibility of probing the structure of the short-period planet. The ability to do this relies on the system being in a quasi-equilibrium state in the sense that the eccentricities are constant on the usual secular time-scale (typically, a few thousand years), and decay on a time-scale which is much longer than the age of the system. Since the equilibrium eccentricity is effectively a function only of observable system parameters and the unknown Love number of the short-period planet, the latter can be determined with accurate measurements of the planet's eccentricity and radius. However, this analysis relies on the assumption that the system is coplanar, a situation which seems unlikely given the high eccentricity of the outer planet. Here we generalize our recent analysis of this fixed-point phenomenon to mutually inclined systems in which the outer body dominates the total angular momentum, and show that (1) the fixed point of coplanar systems is replaced by a limit cycle in eb,, space, where eb is the eccentricity of the inner planet and , is the angle between the periapse lines, with the average value of eb, e(av)b, decreasing and its amplitude of variation increasing with increasing mutual inclination. This behaviour significantly reduces the ability to unambiguously determine the Love number of the short-period planet if the mutual inclination is higher than around 10°. (2) We show that for Q -values less than 106, the HAT-P-13 system cannot have a mutual inclination between 54° and 126° because Kozai oscillations coupled with tidal dissipation would act to quickly move the inclination outside this range, and (3) that the behaviour of retrograde systems is the mirror image of that for prograde systems in the sense that (almost) identical limit cycles exist for a given mutual inclination and , minus this value. (4) We derive a relationship between e(av)b, the equilibrium radius of the short-period planet, its Q -value and its core mass, and show that given current estimates of eb and the planet radius, as well as the lower bound placed on the Q -value by the decay rate of e(av)b, the HAT-P-13 system is likely to be close to prograde coplanar, or have a mutual inclination between 130° and 135°. Lower rather than higher core masses are favoured. (5) An expression for the time-scale for decay of the mutual inclination is derived, revealing that it evolves towards a non-zero value as long as eb > 0 on a time-scale which is much longer than the age of the system. (6) We conclude with a scattering scenario for the origin of the HAT-P-13 system and show that almost identical initial conditions can result in significantly different outer planet eccentricities, stellar obliquities and planet radii. The implications for systems with high stellar obliquities such as HAT-P-7 and WASP-17 are briefly discussed. [source]

Orthotopic, but Reversed Implantation of the Liver Allograft in Situs Inversus Totalis,A Simple New Approach to a Difficult Problem

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009
S. C. Rayhill
Situs inversus totalis is a rare congenital anomaly in which the heart and abdominal organs are oriented in a mirror image of normal. It provides a unique challenge as there is no established technique for liver transplantation in these patients. Employing two major alterations from our standard technique, a liver was transplanted in the left subphrenic space of a patient with situs inversus totalis. First, the liver was flipped 180° from right to left (facing backward). Second, a reversed cavaplasty (anterior, not posterior, donor suprahepatic caval incision) was performed. Otherwise, it was standard, with end-to-end anastomoses of the portal vein, hepatic artery and bile duct. Three years after the entirely uneventful transplant, the recipient continues to enjoy the benefits of a normally functioning liver. The described technique prevented torsion, kinking and tension on the anastomosed structures by allowing the liver to sit naturally in an anatomical position in the left hepatic fossa. As it required no special measurements or maneuvers, the technique was easy to execute and required no donor liver size restrictions. This novel technique, with a reversed cavaplasty and a 180° right-to-left flip of the liver into a left-sided hepatic fossa, may be ideal for situs inversus totalis. [source]

First look at RNA in l -configuration

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2004
RNA in l -configuration
Nucleic acid molecules in the mirror image or l -configuration are unknown in nature and are extraordinarily resistant to biological degradation. The identification of functional l -oligonucleotides called Spiegelmers offers a novel approach for drug discovery based on RNA. The sequence r(CUGGGCGG)·r(CCGCCUGG) was chosen as a model system for structural analysis of helices in the l -configuration as the structure of the d -form of this sequence has previously been determined in structural studies of 5S RNA domains, in particular domain E of the Thermus flavus 5S rRNA [Perbandt et al. (2001), Acta Cryst. D57, 219,224]. Unexpectedly, the results of crystallization trials showed little similarity between the d - and the l -forms of the duplex in either the crystallization hits or the diffraction performance. The crystal structure of this l -RNA duplex has been determined at 1.9,Å resolution with Rwork and Rfree of 23.8 and 28.6%, respectively. The crystals belong to space group R32, with unit-cell parameters a = 45.7, c = 264.6,Å. Although there are two molecules in the asymmetric unit rather than one, the structure of the l -form arranges helical pairs in a head-to-tail fashion to form pseudo-continuous infinite helices in the crystal as in the d -form. On the other hand, the wobble-like G·C+ base pair seen in the D-RNA analogue does not appear in the l -RNA duplex, which forms a regular double-helical structure with typical Watson,Crick base pairing. [source]

Selection of D -Amino-Acid Peptides That Bind to Alzheimer's Disease Amyloid Peptide A,1,42 by Mirror Image Phage Display

CHEMBIOCHEM, Issue 8 2003
Katja Wiesehan Dr.
Abstract A mirror image phage display approach was used to identify novel and highly specific ligands for Alzheimer's disease amyloid peptide A,(1,42). A randomized 12-mer peptide library presented on M13 phages was screened for peptides with binding affinity for the mirror image of A,(1,42). After four rounds of selection and amplification the peptides were enriched with a dominating consensus sequence. The mirror image of the most representative peptide (D -pep) was shown to bind A,(1,42) with a dissociation constant in the submicromolar range. Furthermore, in brain tissue sections derived from patients that suffered from Alzheimer's disease, amyloid plaques and leptomeningeal vessels containing A, amyloid were stained specifically with a fluorescence-labeled derivative of D -pep. Fibrillar deposits derived from other amyloidosis were not labeled by D -pep. Possible applications of this novel and highly specific A, ligand in diagnosis and therapy of Alzheimer's disease are discussed. [source]

Geometrical and algebraic approach to central molecular chirality: A chirality index and an Aufbau description of tetrahedral molecules

CHIRALITY, Issue 7 2006
Salvatore Capozziello
Abstract On the basis of empirical Fischer projections, we develop an algebraic approach to the central molecular chirality of tetrahedral molecules. The elements of such an algebra are obtained from the 24 projections which a single chiral tetrahedron can generate in S and R absolute configurations. They constitute a matrix representation of the O(4) orthogonal group. According to this representation, given a molecule with n chiral centres, it is possible to define an "index of chirality , , {n, p}", where n is the number of stereogenic centres of the molecule and p the number of permutations observed under rotations and superimpositions of the tetrahedral molecule to its mirror image. The chirality index not only assigns the global chirality of a given tetrahedral chain, but indicates also a way to predict the same property for new compounds, which can be built up consistently. Chirality 18:462,468, 2006. © 2006 Wiley-Liss, Inc. [source]

SHAPE ANALYSIS OF SYMMETRIC STRUCTURES: QUANTIFYING VARIATION AMONG INDIVIDUALS AND ASYMMETRY

EVOLUTION, Issue 10 2002
Christian Peter Klingenberg
Abstract., Morphometric studies often consider parts with internal left-right symmetry, for instance, the vertebrate skull. This type of symmetry is called object symmetry and is distinguished from matching symmetry, in which two separate structures exist as mirror images of each other, one on each body side. We explain a method for partitioning the total shape variation of landmark configurations with object symmetry into components of symmetric variation among individuals and asymmetry. This method is based on the Procrustes superimposition of the original and a reflected copy of each landmark configuration and is compatible with the two-factor ANOVA model customary in studies of fluctuating asymmetry. We show a fully multivariate framework for testing the effects in the two-factor model with MANOVA statistics, which also applies to shapes with matching symmetry. We apply the new methods in a small case study of pharyngeal jaws of the Neotropical cichlid fish Amphilophus citrinellus. The analysis revealed that the symmetric component of variation in the pharyngeal jaws is dominated by the contrast between two alternative trophic morphs in this species and that there is subtle but statistically significant directional asymmetry. Finally, we provide some general recommendations for morphometric studies of symmetric shapes. [source]

Large-Scale Synthesis, Annealing, Purification, and Magnetic Properties of Crystalline Helical Carbon Nanotubes with Symmetrical Structures,

ADVANCED FUNCTIONAL MATERIALS, Issue 9 2007
J. Tang
Abstract Crystalline helical carbon nanotubes (HCNTs) are synthesized as the main products in the pyrolysis of acetylene at 450,°C over Fe nanoparticles generated by means of a combined sol,gel/reduction method. Transmission electron microscopy (TEM) images reveal that there are two HCNTs attached to each Fe3C nanoparticle, and that the two HCNTs are mirror images of each other. Annealing in Ar at 750,°C and purification by immersion in hot (90,°C) HCl solution do not significantly change the structure of the HCNTs, despite the partial removal of Fe nanoparticles by the latter treatment. The magnetic properties of the as-prepared, annealed, and purified HCNTs have been systematically examined. The annealed sample shows relatively high magnetization due to the ferromagnetic ,-Fe nanoparticles encapsulated in the HCNT nodes. In the case of HCl treatment, relatively pure HCNTs are obtained by the removal of ferromagnetic nanoparticles from the double-HCNT nodes. The effects of the amount of catalyst used in the synthesis process on the morphology and yield of the carbon products have also been investigated. [source]

Spontaneous segregation on a hybrid chiral surface

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 10 2008
Szabelski
Abstract Segregation of enantiomers in two-dimensional adsorbed layers is a process that is usually controlled by anisotropic directional interactions between adsorbed molecules. In this contribution, we propose a simple theoretical model in which the chiral segregation occurs even though the lateral interactions are neglected. In particular, we consider a solid surface composed of two domains with different patterns of active sites being mirror images of each other. The domains of opposite handedness represent crystal facets of a composite chiral material which are adjoined to form a heterochiral adsorbing surface. To explore equilibrium properties of the system, we use Canonical Ensemble Monte Carlo method for a square lattice. The influence of factors such as energetic properties of the surface and density of the adsorbed layer on the extent of separation is examined. The obtained results indicate that effective two-dimensional separation on the hybrid chiral surface assumed in our model can be achieved only at sufficiently low adsorbate densities. The results also suggest that the segregation on the hybrid surface would be a promising method of enantiodiscrimination for those chiral molecules which do not exhibit strong lateral interactions. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008 [source]

Principal component analysis of landmarks from reversible images

Three-Dimensional Serial Section Computer Reconstruction of the Arrangement of the Structural Components of the Parabronchus of the Ostrich, Struthio Camelus Lung

THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 11 2009
John N. Maina
,Cubed' three-dimensional computer reconstruction (from serial sections) of the exchange tissue (parenchyma) of the lung of the ostrich, Struthio camelus showing the profuse anastomoses of the air capillaries (shown in cyan) and the blood capillaries (shown in red). While the two terminal respiratory units interdigitate very copiously as they interface intimately, thereby optimizing the respiratory surface area, regarding their size and shape, they are not mirror images as has previously been reported nor do they spatially form a counter-current arrangement, as they have been commonly modelled. See Maina et al., "Three-Dimensional Serial Section Computer Reconstruction of the Arrangement of the Structural Components of the Parabronchus of the Ostrich, Struthio Camelus Lung," on page 1685, in this issue. [source]

7-Amino-5-methyl-2-phenyl-6-(phenyldiazenyl)pyrazolo[1,5- a]pyrimidine crystallizes with Z, = 2: pseudosymmetry and the formation of complex sheets built from N,H...N and C,H...,(arene) hydrogen bonds

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
Jaime Portilla
The title compound, C19H16N6, crystallizes with Z, = 2 in the space group P21/n. The two molecules in the selected asymmetric unit are approximate mirror images of one another; most corresponding pairs of atoms are related by an approximate half-cell translation along [100]. Each molecule contains an intramolecular N,H...N hydrogen bond and the molecules are linked into complex sheets by a combination of two intermolecular N,H...N and four C,H...,(arene) hydrogen bonds. Comparisons are made with some other 7-aminopyrazolo[1,5- a]pyrimidines. [source]

THE ,FRYING PANS' OF THE EARLY BRONZE AGE AEGEAN: AN EXPERIMENTAL APPROACH TO THEIR POSSIBLE USE AS LIQUID MIRRORS,

ARCHAEOMETRY, Issue 4 2009
D. A. PAPATHANASSOGLOU
The so-called ,frying pans' are peculiar vessels, most of them made of terracotta, flat and shallow, usually decorated on the outside part and dated to the Early Bronze Age. They were unearthed mostly in the Cyclades, in Crete and on the Helladic mainland. There are also a few artefacts made of stone and of bronze, from the Cyclades and Asia Minor, respectively. The intended purpose of these objects is disputed. Several interpretations exist for their function, the earliest one being that of liquid mirror vessels. We investigated the mirror hypothesis experimentally, by testing trays with attributes similar to those of the original ,frying pans', filled with a series of liquids familiar to the people of the time and the place where those vessels were made. The criterion employed was the contrast of mirror images. We conclude that, provided that some minimal prerequisites are met, the ,frying pans' are quite appropriate as liquid mirror vessels. [source]