Mapping cortical brain asymmetry in 17,141 healthy individuals worldwide via the ENIGMA Consortium.

PubMed

Kong, Xiang-Zhen; Mathias, Samuel R; Guadalupe, Tulio; Glahn, David C; Franke, Barbara; Crivello, Fabrice; Tzourio-Mazoyer, Nathalie; Fisher, Simon E; Thompson, Paul M; Francks, Clyde

2018-05-29

Hemispheric asymmetry is a cardinal feature of human brain organization. Altered brain asymmetry has also been linked to some cognitive and neuropsychiatric disorders. Here, the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Consortium presents the largest-ever analysis of cerebral cortical asymmetry and its variability across individuals. Cortical thickness and surface area were assessed in MRI scans of 17,141 healthy individuals from 99 datasets worldwide. Results revealed widespread asymmetries at both hemispheric and regional levels, with a generally thicker cortex but smaller surface area in the left hemisphere relative to the right. Regionally, asymmetries of cortical thickness and/or surface area were found in the inferior frontal gyrus, transverse temporal gyrus, parahippocampal gyrus, and entorhinal cortex. These regions are involved in lateralized functions, including language and visuospatial processing. In addition to population-level asymmetries, variability in brain asymmetry was related to sex, age, and intracranial volume. Interestingly, we did not find significant associations between asymmetries and handedness. Finally, with two independent pedigree datasets ( n = 1,443 and 1,113, respectively), we found several asymmetries showing significant, replicable heritability. The structural asymmetries identified and their variabilities and heritability provide a reference resource for future studies on the genetic basis of brain asymmetry and altered laterality in cognitive, neurological, and psychiatric disorders.

Subtasks affecting step-length asymmetry in post-stroke hemiparetic walking.

PubMed

Kim, Woo-Sub

2016-10-01

This study was performed to investigate whether components from trunk progression (TP) and step length were related to step length asymmetry in walking in patients with hemiparesis. Gait analysis was performed for participants with hemiparesis and healthy controls. The distance between the pelvis and foot in the anterior-posterior axis was calculated at initial-contact. Step length was partitioned into anterior foot placement (AFP) and posterior foot placement (PFP). TP was partitioned into anterior trunk progression (ATP) and posterior trunk progression (PTP). The TP pattern and step length pattern were defined to represent intra-TP and intra-step spatial balance, respectively. Of 29 participants with hemiparesis, nine participants showed longer paretic step length, eight participants showed symmetric step length, and 12 participants showed shorter paretic step length. For the hemiparesis group, linear regression analysis showed that ATP asymmetry, AFP asymmetry, and TP patterns had significant predictability regarding step length asymmetry. Prolonged paretic ATP and shortened paretic AFP was the predominant pattern in the hemiparesis group, even in participants with symmetric step length. However, some participants showed same direction of ATP and AFP asymmetry. These findings indicate the following: (1) ATP asymmetries should be observed to determine individual characteristics of step length asymmetry, and (2) TP patterns can provide complementary information for non-paretic limb compensation. Copyright © 2016 Elsevier B.V. All rights reserved.

Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography

PubMed Central

Liu, Yaou; Duan, Yunyun; Li, Kuncheng

2015-01-01

The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain. PMID:26539535

The influence of sex chromosome aneuploidy on brain asymmetry.

PubMed

Rezaie, Roozbeh; Daly, Eileen M; Cutter, William J; Murphy, Declan G M; Robertson, Dene M W; DeLisi, Lynn E; Mackay, Clare E; Barrick, Thomas R; Crow, Timothy J; Roberts, Neil

2009-01-05

The cognitive deficits present in individuals with sex chromosome aneuploidies suggest that hemispheric differentiation of function is determined by an X-Y homologous gene [Crow (1993); Lancet 342:594-598]. In particular, females with Turner's syndrome (TS) who have only one X-chromosome exhibit deficits of spatial ability whereas males with Klinefelter's syndrome (KS) who possess a supernumerary X-chromosome are delayed in acquiring words. Since spatial and verbal abilities are generally associated with right and left hemispheric function, such deficits may relate to anomalies of cerebral asymmetry. We therefore applied a novel image analysis technique to investigate the relationship between sex chromosome dosage and structural brain asymmetry. Specifically, we tested Crow's prediction that the magnitude of the brain torque (i.e., a combination of rightward frontal and leftward occipital asymmetry) would, as a function of sex chromosome dosage, be respectively decreased in TS women and increased in KS men, relative to genotypically normal controls. We found that brain torque was not significantly different in TS women and KS men, in comparison to controls. However, TS women exhibited significantly increased leftward brain asymmetry, restricted to the posterior of the brain and focused on the superior temporal and parietal-occipital association cortex, while KS men showed a trend for decreased brain asymmetry throughout the frontal lobes. The findings suggest that the number of sex chromosomes influences the development of brain asymmetry not simply to modify the torque but in a complex pattern along the antero-posterior axis. 2008 Wiley-Liss, Inc.

Atypical Cerebral Lateralisation in Adults with Compensated Developmental Dyslexia Demonstrated Using Functional Transcranial Doppler Ultrasound

ERIC Educational Resources Information Center

Illingworth, Sarah; Bishop, Dorothy V. M.

2009-01-01

Functional transcranial Doppler ultrasound (fTCD) is a relatively new and non-invasive technique that assesses cerebral lateralisation through measurements of blood flow velocity in the middle cerebral arteries. In this study fTCD was used to compare functional asymmetry during a word generation task between a group of 30 dyslexic adults and a…

Hemispheric Asymmetry for Linguistic Prosody: A Study of Stress Perception in Croatian

ERIC Educational Resources Information Center

Mildner, Vesna

2004-01-01

The aim of the study was to test for possible functional cerebral asymmetry in processing one segment of linguistic prosody, namely word stress, in Croatian. The test material consisted of eight tokens of the word "pas" under a falling accent, varying only in vowel duration between 119 and 185ms, attached to the end of a frame sentence. The…

Structural connectivity asymmetry in the neonatal brain.

PubMed

Ratnarajah, Nagulan; Rifkin-Graboi, Anne; Fortier, Marielle V; Chong, Yap Seng; Kwek, Kenneth; Saw, Seang-Mei; Godfrey, Keith M; Gluckman, Peter D; Meaney, Michael J; Qiu, Anqi

2013-07-15

Asymmetry of the neonatal brain is not yet understood at the level of structural connectivity. We utilized DTI deterministic tractography and structural network analysis based on graph theory to determine the pattern of structural connectivity asymmetry in 124 normal neonates. We tracted white matter axonal pathways characterizing interregional connections among brain regions and inferred asymmetry in left and right anatomical network properties. Our findings revealed that in neonates, small-world characteristics were exhibited, but did not differ between the two hemispheres, suggesting that neighboring brain regions connect tightly with each other, and that one region is only a few paths away from any other region within each hemisphere. Moreover, the neonatal brain showed greater structural efficiency in the left hemisphere than that in the right. In neonates, brain regions involved in motor, language, and memory functions play crucial roles in efficient communication in the left hemisphere, while brain regions involved in emotional processes play crucial roles in efficient communication in the right hemisphere. These findings suggest that even at birth, the topology of each cerebral hemisphere is organized in an efficient and compact manner that maps onto asymmetric functional specializations seen in adults, implying lateralized brain functions in infancy. Copyright © 2013 Elsevier Inc. All rights reserved.

Cerebral specialization for speech production in persons with Down syndrome.

PubMed

Heath, M; Elliott, D

1999-09-01

The study of cerebral specialization in persons with Down syndrome (DS) has revealed an anomalous pattern of organization. Specifically, dichotic listening studies (e.g., Elliott & Weeks, 1993) have suggested a left ear/right hemisphere dominance for speech perception for persons with DS. In the current investigation, the cerebral dominance for speech production was examined using the mouth asymmetry technique. In right-handed, nonhandicapped subjects, mouth asymmetry methodology has shown that during speech, the right side of the mouth opens sooner and to a larger degree then the left side (Graves, Goodglass, & Landis, 1982). The phenomenon of right mouth asymmetry (RMA) is believed to reflect the direct access that the musculature on the right side of the face has to the left hemisphere's speech production systems. This direct access may facilitate the transfer of innervatory patterns to the muscles on the right side of the face. In the present study, the lateralization for speech production was investigated in 10 right-handed participants with DS and 10 nonhandicapped subjects. A RMA at the initiation and end of speech production occurred for subjects in both groups. Surprisingly, the degree of asymmetry between groups did not differ, suggesting that the lateralization of speech production is similar for persons with and persons without DS. These results support the biological dissociation model (Elliott, Weeks, & Elliott, 1987), which holds that persons with DS display a unique dissociation between speech perception (right hemisphere) and speech production (left hemisphere). Copyright 1999 Academic Press.

The Role of Hemispheral Asymmetry and Regional Activity of Quantitative EEG in Children with Stuttering

ERIC Educational Resources Information Center

Ozge, Aynur; Toros, Fevziye; Comelekoglu, Ulku

2004-01-01

We investigated the role of delayed cerebral maturation, hemisphere asymmetry and regional differences in children with stuttering and healthy controls during resting state and hyperventilation, using conventional EEG techniques and quantitative EEG (QEEG) analysis. This cross-sectional case control study included 26 children with stuttering and…

[Dextrals and sinistrals (right-handers and left-handers): specificity of interhemispheric brain asymmetry and EEG coherence parameters].

PubMed

Zhavoronkova, L A

2007-01-01

Data of literature about morphological, functional and biochemical specificity of the brain interhemispheric asymmetry of healthy right-handers and left-handers and about peculiarity of dynamics of cerebral pathology in patients with different individual asymmetry profiles are presented at the present article. Results of our investigation by using coherence parameters of electroencephalogram (EEG) in healthy right-handers and left-handers in state of rest, during functional tests and sleeping and in patients with different forms of the brain organic damage were analyzed too. EEG coherence analysis revealed the reciprocal changing of alpha-beta and theta-delta spectral bands in right-handers whilein left-handers synchronous changing of all EEG spectral bands were observed. Data about regional-frequent specificity of EEG coherence, peculiarity of EEG asymmetry in right-handers and left-handers, aslo about specificity of EEG spectral band genesis and point of view about a role of the brain regulator systems in forming of interhemispheric asymmetry in different functional states allowed to propose the conception about principle of interhermispheric brain asymmetry formation in left-handers and left-handers. Following this conception in dextrals elements of concurrent (summary-reciprocal) cooperation are predominant at the character of interhemispheric and cortical-subcortical interaction while in sinistrals a principle of concordance (supplementary) is preferable. These peculiarities the brain organization determine, from the first side, the quicker revovery of functions damaged after cranio-cerebral trauma in left-handers in comparison right-handers and from the other side - they determine the forming of the more expressed pathology in the remote terms after exposure the low dose of radiation.

Parcellations and Hemispheric Asymmetries of Human Cerebral Cortex Analyzed on Surface-Based Atlases

PubMed Central

Glasser, Matthew F.; Dierker, Donna L.; Harwell, John; Coalson, Timothy

2012-01-01

We report on surface-based analyses that enhance our understanding of human cortical organization, including its convolutions and its parcellation into many distinct areas. The surface area of human neocortex averages 973 cm2 per hemisphere, based on cortical midthickness surfaces of 2 cohorts of subjects. We implemented a method to register individual subjects to a hybrid version of the FreeSurfer “fsaverage” atlas whose left and right hemispheres are in precise geographic correspondence. Cortical folding patterns in the resultant population-average “fs_LR” midthickness surfaces are remarkably similar in the left and right hemispheres, even in regions showing significant asymmetry in 3D position. Both hemispheres are equal in average surface area, but hotspots of surface area asymmetry are present in the Sylvian Fissure and elsewhere, together with a broad pattern of asymmetries that are significant though small in magnitude. Multiple cortical parcellation schemes registered to the human atlas provide valuable reference data sets for comparisons with other studies. Identified cortical areas vary in size by more than 2 orders of magnitude. The total number of human neocortical areas is estimated to be ∼150 to 200 areas per hemisphere, which is modestly larger than a recent estimate for the macaque. PMID:22047963

A pattern of cerebral perfusion anomalies between Major Depressive Disorder and Hashimoto Thyroiditis

PubMed Central

2011-01-01

Background This study aims to evaluate relationship between three different clinical conditions: Major Depressive Disorders (MDD), Hashimoto Thyroiditis (HT) and reduction in regional Cerebral Blood Flow (rCBF) in order to explore the possibility that patients with HT and MDD have specific pattern(s) of cerebral perfusion. Methods Design: Analysis of data derived from two separate data banks. Sample: 54 subjects, 32 with HT (29 women, mean age 38.8 ± 13.9); 22 without HT (19 women, mean age 36.5 ± 12.25). Assessment: Psychiatric diagnosis was carried out by Simplified Composite International Diagnostic Interview (CIDIS) using DSM-IV categories; cerebral perfusion was measured by 99 mTc-ECD SPECT. Statistical analysis was done through logistic regression. Results MDD appears to be associated with left frontal hypoperfusion, left temporal hypoperfusion, diffuse hypoperfusion and parietal perfusion asymmetry. A statistically significant association between parietal perfusion asymmetry and MDD was found only in the HT group. Conclusion In HT, MDD is characterized by a parietal flow asymmetry. However, the specificity of rCBF in MDD with HT should be confirmed in a control sample with consideration for other health conditions. Moreover, this should be investigated with a longitudinally designed study in order to determine a possible pathogenic cause. Future studies with a much larger sample size should clarify whether a particular perfusion pattern is associated with a specific course or symptom cluster of MDD. PMID:21910915

Planum Temporale Asymmetries Correlate with Corpus Callosum Axon Fiber Density in Chimpanzees (Pan troglodytes)

PubMed Central

Hopkins, William D.; Pilger, John F.; Storz, Rachel; Ambrose, Alex; Hof, Patrick R.; Sherwood, Chet C.

2012-01-01

The corpus callosum (CC) is the major white matter tract that connects the two cerebral hemispheres. Some have theorized that individual differences in behavioral and brain asymmetries are linked to variation in the density of axon fibers that traverse different sections of the CC. In this study, we examined whether variation in axon fiber density in the CC was associated with variation in asymmetries in the planum temporale (PT) in a sample of 20 post-mortem chimpanzee brains. We further tested for sex differences in small and large CC fiber proportions and density in the chimpanzees. We found that the distribution of small and large fibers within the CC of chimpanzees follows a similar pattern to those reported in humans. We also found that chimpanzees with larger asymmetries in the PT had fewer large fibers in the posterior portion of the CC, particularly among females. As has been reported in human brains, the findings reported here indicate that individual differences in brain asymmetries are associated with variation in interhemispheric connectivity as manifest in axon fiber density and size. PMID:22766214

Posterior N1 asymmetry to English and Welsh words in Early and Late English-Welsh bilinguals.

PubMed

Grossi, Giordana; Savill, Nicola; Thomas, Enlli; Thierry, Guillaume

2010-09-01

We investigated the lateralization of the posterior event-related potential (ERP) component N1 (120-170 ms) to written words in two groups of bilinguals. Fourteen Early English-Welsh bilinguals and 14 late learners of Welsh performed a semantic categorization task on separate blocks of English and Welsh words. In both groups, the N1 was strongly lateralized over the left posterior sites for both languages. A robust correlation was found between N1 asymmetry for English and N1 asymmetry for Welsh words in both groups. Furthermore, in Late Bilinguals, the N1 asymmetry for Welsh words increased with years of experience in Welsh. These data suggest that, in Late Bilinguals, the lateralization of neural circuits involved in written word recognition for the second language is associated to the organization for the first language, and that increased experience with the second language is associated to a larger functional cerebral asymmetry in favor of the left hemisphere. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Cerebral asymmetry and behavioral lateralization in rats chronically lacking n-3 polyunsaturated fatty acids.

PubMed

Vancassel, Sylvie; Aïd, Sabah; Pifferi, Fabien; Morice, Elise; Nosten-Bertrand, Marika; Chalon, Sylvie; Lavialle, Monique

2005-11-15

Anatomic and functional brain lateralization underlies hemisphere specialization for cognitive and motor control, and deviations from the normal patterns of asymmetry appear to be related to behavioral deficits. Studies on n-3 polyunsaturated fatty acid (PUFA) deficiency and behavioral impairments led us to postulate that a chronic lack of n-3 PUFA can lead to changes in lateralized behavior by affecting structural or neurochemical patterns of asymmetry in motor-related brain structures. We compared the effects of a chronic n-3 PUFA deficient diet with a balanced diet on membrane phospholipid fatty acids composition and immunolabeling of choline acetyltransferase (ChAt), as a marker of cholinergic neurons, in left and right striatum of rats. Lateral motor behavior was assessed by rotation and paw preference. Control rats had an asymmetric PUFA distribution with a right behavioral preference, whereas ChAt density was symmetrical. In deficient rats, the cholinergic neuron density was 30% lower on the right side, associated with a loss of PUFA asymmetry and behavior laterality. They present higher rotation behavior, and significantly more of them failed the handedness test. These results indicate that a lack of n-3 PUFA is linked with a lateral behavior deficit, possibly leading to cognitive disturbances.

Corticospinal tract asymmetry and handedness in right- and left-handers by diffusion tensor tractography.

PubMed

Seizeur, Romuald; Magro, Elsa; Prima, Sylvain; Wiest-Daesslé, Nicolas; Maumet, Camille; Morandi, Xavier

2014-03-01

Cerebral hemispheres represent both structural and functional asymmetry, which differs among right- and left-handers. The left hemisphere is specialised for language and task execution of the right hand in right-handers. We studied the corticospinal tract in right- and left-handers by diffusion tensor imaging and tractography. The present study aimed at revealing a morphological difference resulting from a region of interest (ROI) obtained by functional MRI (fMRI). Twenty-five healthy participants (right-handed: 15, left-handed: 10) were enrolled in our assessment of morphological, functional and diffusion tensor MRI. Assessment of brain fibre reconstruction (tractography) was done using a deterministic algorithm. Fractional anisotropy (FA) and mean diffusivity (MD) were studied on the tractography traces of the reference slices. We observed a significant difference in number of leftward fibres based on laterality. The significant difference in regard to FA and MD was based on the slices obtained at different levels and the laterality index. We found left-hand asymmetry and right-hand asymmetry, respectively, for the MD and FA. Our study showed the presence of hemispheric asymmetry based on laterality index in right- and left-handers. These results are inconsistent with some studies and consistent with others. The reported difference in hemispheric asymmetry could be related to dexterity (manual skill).

Divergent regional patterns of cerebral hypoperfusion and gray matter atrophy in mild cognitive impairment patients.

PubMed

Wirth, Miranka; Pichet Binette, Alexa; Brunecker, Peter; Köbe, Theresa; Witte, A Veronica; Flöel, Agnes

2017-03-01

Reductions of cerebral blood flow and gray matter structure have been implicated in early pathogenesis of Alzheimer's disease, potentially providing complementary information. The present study evaluated regional patterns of cerebral hypoperfusion and atrophy in patients with mild cognitive impairment and healthy older adults. In each participant, cerebral perfusion and gray matter structure were extracted within selected brain regions vulnerable to Alzheimer's disease using magnetic resonance imaging. Measures were compared between diagnostic groups with/without adjustment for covariates. In mild cognitive impairment patients, cerebral blood flow was significantly reduced in comparison with healthy controls in temporo-parietal regions and the basal ganglia in the absence of local gray matter atrophy. By contrast, gray matter structure was significantly reduced in the hippocampus in the absence of local hypoperfusion. Both, cerebral perfusion and gray matter structure were significantly reduced in the entorhinal and isthmus cingulate cortex in mild cognitive impairment patients compared with healthy older adults. Our results demonstrated partly divergent patterns of temporo-parietal hypoperfusion and medial-temporal atrophy in mild cognitive impairment patients, potentially indicating biomarker sensitivity to dissociable pathological mechanisms. The findings support applicability of cerebral perfusion and gray matter structure as complementary magnetic resonance imaging-based biomarkers in early Alzheimer's disease detection, a hypothesis to be further evaluated in longitudinal studies.

Sylvian Fissure Asymmetries in Nonhuman Primates Revisited: A Comparative MRI Study

PubMed Central

Hopkins, William D.; Pilcher, Dawn L.; MacGregor, Leslie

2007-01-01

Magnetic resonance images (MRI) were collected in a sample of 28 apes, 16 Old World monkeys and 8 New World monkeys. The length of the sylvian fissure (SF) and the superior temporal sulcus (STS) was traced in each hemisphere from three regions of the cerebral cortex. These three regions were labeled according to their position on the sagittal plane as lateral, medial and insular. It was hypothesized that the length and asymmetry of these fissures would be dependent on the region of measurement and that a leftward asymmetry in the SF and STS would be more robust in the great ape sample than for the monkeys. The results indicated within the ape sample a population-level leftward asymmetry in the medial and insular regions of the SF. Within the Old and New World monkey samples, the SF was leftward in the medial region at the population level, but not at the insular region. Additionally, the Old World monkeys exhibited a population-level rightward lateral SF and a rightward lateral STS. No other families exhibited population-level asymmetries in the lateral region of the SF or in any region of the STS. These results are consistent with findings reported in apes and, to a lesser extent, monkeys. MRI has excellent potential for comparing neuroanatomy across taxonomic families that will help future investigations. PMID:11326134

Control of Angular Momentum during Walking in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Bruijn, Sjoerd M.; Meyns, Pieter; Jonkers, Ilse; Kaat, Desloovere; Duysens, Jacques

2011-01-01

Children with hemiparetic Cerebral Palsy (CP) walk with marked asymmetries. For instance, we have recently shown that they have less arm swing on the affected side, and more arm swing at the unaffected side. Such an increase in arm swing at the unaffected side may be aimed at controlling total body angular momentum about the vertical axis,…

Electron impact ionization of O2 and the interference effect from forward-backward asymmetry

NASA Astrophysics Data System (ADS)

Chowdhury, Madhusree Roy; Tribedi, Lokesh C.

2017-08-01

Absolute double differential cross sections (DDCSs) of secondary electrons emitted from O2 under the impact of 7 keV electrons were measured for different emission angles between 30° and 145° having energies from 1-600 eV. The forward-backward angular asymmetry was observed from angular distribution of the DDCS of secondary electrons. The asymmetry parameter, thus obtained from the DDCS of two complementary angles, showed a clear signature of interference oscillation. The Cohen-Fano model of Young type electron interference at a molecular double slit is found to provide a good fit to the observed oscillatory structures. The present observation is in qualitative agreement with the recent results obtained from photoionization.

SU(2) Flavor Asymmetry of the Proton Sea in Chiral Effective Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKenney, J. R.; Sato Gonzalez, Nobuo; Melnitchouk, Wally

We refine the computation of themore » $$\\bar{d}$$ - $$\\bar{u}$$ flavor asymmetry in the proton sea with a complementary effort to reveal the dynamics of pion exchange in high-energy processes. In particular, we discuss the efficacy of pion exchange models to simultaneously describe leading neutron electroproduction at HERA along with the $$\\bar{d}$$ - $$\\bar{u}$$ flavor asymmetry in the proton. A detailed χ 2 analysis of the ZEUS and H1 data, when combined with constraints on the pion flux from Drell-Yan data, allows regions of applicability of one-pion exchange to be delineated. Based on the fit results, we also address a possible estimate for leading proton structure functions in upcoming tagged deep-inelastic scattering experiments at Jefferson Lab on the deuteron with forward protons.« less

Posed versus spontaneous facial expressions are modulated by opposite cerebral hemispheres.

PubMed

Ross, Elliott D; Pulusu, Vinay K

2013-05-01

Clinical research has indicated that the left face is more expressive than the right face, suggesting that modulation of facial expressions is lateralized to the right hemisphere. The findings, however, are controversial because the results explain, on average, approximately 4% of the data variance. Using high-speed videography, we sought to determine if movement-onset asymmetry was a more powerful research paradigm than terminal movement asymmetry. The results were very robust, explaining up to 70% of the data variance. Posed expressions began overwhelmingly on the right face whereas spontaneous expressions began overwhelmingly on the left face. This dichotomy was most robust for upper facial expressions. In addition, movement-onset asymmetries did not predict terminal movement asymmetries, which were not significantly lateralized. The results support recent neuroanatomic observations that upper versus lower facial movements have different forebrain motor representations and recent behavioral constructs that posed versus spontaneous facial expressions are modulated preferentially by opposite cerebral hemispheres and that spontaneous facial expressions are graded rather than non-graded movements. Published by Elsevier Ltd.

Speech processing: from peripheral to hemispheric asymmetry of the auditory system.

PubMed

Lazard, Diane S; Collette, Jean-Louis; Perrot, Xavier

2012-01-01

Language processing from the cochlea to auditory association cortices shows side-dependent specificities with an apparent left hemispheric dominance. The aim of this article was to propose to nonspeech specialists a didactic review of two complementary theories about hemispheric asymmetry in speech processing. Starting from anatomico-physiological and clinical observations of auditory asymmetry and interhemispheric connections, this review then exposes behavioral (dichotic listening paradigm) as well as functional (functional magnetic resonance imaging and positron emission tomography) experiments that assessed hemispheric specialization for speech processing. Even though speech at an early phonological level is regarded as being processed bilaterally, a left-hemispheric dominance exists for higher-level processing. This asymmetry may arise from a segregation of the speech signal, broken apart within nonprimary auditory areas in two distinct temporal integration windows--a fast one on the left and a slower one on the right--modeled through the asymmetric sampling in time theory or a spectro-temporal trade-off, with a higher temporal resolution in the left hemisphere and a higher spectral resolution in the right hemisphere, modeled through the spectral/temporal resolution trade-off theory. Both theories deal with the concept that lower-order tuning principles for acoustic signal might drive higher-order organization for speech processing. However, the precise nature, mechanisms, and origin of speech processing asymmetry are still being debated. Finally, an example of hemispheric asymmetry alteration, which has direct clinical implications, is given through the case of auditory aging that mixes peripheral disorder and modifications of central processing. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Is complementary and alternative therapy effective for women in the climacteric period?

PubMed

Kim, Mi Young; Choi, Seung Do; Ryu, Aeli

2015-04-01

Vasomotor symptoms start about 2 years prior to menopause in women who are approaching menopause, and early menopause symptoms appear including emotional disturbance and anxiety, followed by physical changes such as vaginal dryness, urinary incontinence and skin wrinkles. As time progresses, osteoporosis, cardiovascular diseases, and dementia occur consecutively. Hormone therapy is primarily considered for the relief of menopause symptoms in postmenopausal women. However, as hormone replacement has emerged as a therapy that increases the potential risk of thrombosis, cerebral infarction and breast cancer, complementary and alternative medicine has drawn much attention. This study aimed to examine the types and effects of evidence-based complementary and alternative therapies that are currently used.

Lean Mass Asymmetry Influences Force and Power Asymmetry During Jumping in Collegiate Athletes

PubMed Central

Bell, David R.; Sanfilippo, Jennifer L.; Binkley, Neil; Heiderscheit, Bryan C.

2015-01-01

The purpose of this investigation was to: (1) examine how asymmetry in lower extremity lean mass influenced force and power asymmetry during jumping, (2) determine how power and force asymmetry affected jump height, and (3) report normative values in collegiate athletes. Force and power were assessed from each limb using bilateral force plates during a countermovement jump in 167 Division 1 athletes (mass=85.7±20.3kg, age=20.0±1.2years, 103M/64F). Lean mass of the pelvis, thigh, and shank was assessed via dual-energy X-ray absorptiometry. Percent asymmetry was calculated for lean mass at each region (pelvis, thigh, and shank) as well as force and power. Forward stepwise regressions were performed to determine the influence of lean mass asymmetry on force and power asymmetry. Thigh and shank lean mass asymmetry explained 20% of the variance in force asymmetry (R2=0.20, P<0.001), while lean mass asymmetry of the pelvis, thigh and shank explained 25% of the variance in power asymmetry (R2=0.25, P<0.001). Jump height was compared across level of force and power asymmetry (P>0.05) and greater than 10% asymmetry in power tended to decrease performance (effect size>1.0). Ninety-five percent of this population (2.5th to 97.5th percentile) displayed force asymmetry between −11.8 to 16.8% and a power asymmetry between −9.9 to 11.5%. A small percentage (<4%) of these athletes displayed more than 15% asymmetry between limbs. These results demonstrate that lean mass asymmetry in the lower extremity is at least partially responsible for asymmetries in force and power. However, a large percentage remains unexplained by lean mass asymmetry. PMID:24402449

Lean mass asymmetry influences force and power asymmetry during jumping in collegiate athletes.

PubMed

Bell, David R; Sanfilippo, Jennifer L; Binkley, Neil; Heiderscheit, Bryan C

2014-04-01

The purpose of this investigation was to (a) examine how asymmetry in lower extremity lean mass influenced force and power asymmetry during jumping, (b) determine how power and force asymmetry affected jump height, and (c) report normative values in collegiate athletes. Force and power were assessed from each limb using bilateral force plates during a countermovement jump in 167 division 1 athletes (mass = 85.7 ± 20.3 kg, age = 20.0 ± 1.2 years; 103 men and 64 women). Lean mass of the pelvis, thigh, and shank was assessed using dual-energy x-ray absorptiometry. Percent asymmetry was calculated for lean mass at each region (pelvis, thigh, and shank) as well as force and power. Forward stepwise regressions were performed to determine the influence of lean mass asymmetry on force and power asymmetry. Thigh and shank lean mass asymmetry explained 20% of the variance in force asymmetry (R = 0.20, p < 0.001), whereas lean mass asymmetry of the pelvis, thigh, and shank explained 25% of the variance in power asymmetry (R = 0.25, p < 0.001). Jump height was compared across level of force and power asymmetry (p > 0.05) and greater than 10% asymmetry in power tended to decrease the performance (effect size >1.0). Ninety-five percent of this population (2.5th to 97.5th percentile) displayed force asymmetry between -11.8 and 16.8% and a power asymmetry between -9.9 and 11.5%. A small percentage (<4%) of these athletes displayed more than 15% asymmetry between limbs. These results demonstrate that lean mass asymmetry in the lower extremity is at least partially responsible for asymmetries in force and power. However, a large percentage remains unexplained by lean mass asymmetry.

Nasopupillary asymmetry.

PubMed

Arenas, Eduardo; Muñoz, Diana; Matheus, Evelyn; Morales, Diana

2014-01-01

To establish the prevalence of nasopupillary asymmetry (difference in nasopupillary distances) in the population and its relation with the interpupillary distance. A retrospective descriptive study was conducted by reviewing of 1262 medical records. The values of nasopupillary asymmetry and the interpupillary distance were obtained. A statistical analysis was made and the correlation between these variables was established. Seventy-nine percent of the population presented some degree of nasopupillary asymmetry. The interpupillary distance had a very low correlation with the nasopupillary asymmetry (r = 0.074, P = 0.0). It is advisable to use the nasopupillary distance of each eye as a standard measurement.

Dyke-Davidoff-Masson syndrome: case report of fetal unilateral ventriculomegaly and hypoplastic left middle cerebral artery.

PubMed

Piro, Ettore; Piccione, Maria; Marrone, Gianluca; Giuffrè, Mario; Corsello, Giovanni

2013-05-14

Prenatal ultrasonographic detection of unilateral cerebral ventriculomegaly arises suspicion of pathological condition related to cerebrospinal fluid flow obstruction or cerebral parenchimal pathology. Dyke-Davidoff-Masson syndrome is a rare condition characterized by cerebral hemiatrophy, calvarial thickening, skull and facial asymmetry, contralateral hemiparesis, cognitive impairment and seizures. Congenital and acquired types are recognized and have been described, mainly in late childhood, adolescence and adult ages. We describe a female infant with prenatal diagnosis of unilateral left ventriculomegaly in which early brain MRI and contrast enhanced-MRI angiography, showed cerebral left hemiatrophy associated with reduced caliber of the left middle cerebral artery revealing the characteristic findings of the Dyke-Davidoff-Masson syndrome. Prenatal imaging, cerebral vascular anomaly responsible for the cerebral hemiatrophy and the early clinical evolution have never been described before in such a young child and complete the acquired clinical descriptions in older children. Differential diagnosis, genetic investigations, neurophysiologic assessments, short term clinical and developmental follow up are described. Dyke-Davidoff-Masson syndrome must be ruled out in differential diagnosis of fetal unilateral ventriculomegaly. Early clinical assessment, differential diagnosis and cerebral imaging including cerebral MRI angiography allow the clinicians to diagnose also in early infancy this rare condition.

The association between hemispheric specialization for language production and for spatial attention depends on left-hand preference strength.

PubMed

Zago, Laure; Petit, Laurent; Mellet, Emmanuel; Jobard, Gaël; Crivello, Fabrice; Joliot, Marc; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie

2016-12-01

Cerebral lateralization for language production and spatial attention and their relationships with manual preference strength (MPS) were assessed in a sample of 293 healthy volunteers, including 151 left-handers, using fMRI during covert sentence production (PROD) and line bisection judgment (LBJ) tasks, as compared to high- and low-level reference tasks. At the group level, we found the expected complementary hemispheric specialization (HS) with leftward asymmetries for PROD within frontal and temporal regions and rightward asymmetries for LBJ within frontal and posterior occipito-parieto-temporal regions. Individual hemispheric (HLI) and regional (frontal and occipital) lateralization indices (LI) were then calculated on the activation maps for PROD and LBJ. We found a correlation between the degree of rightward cerebral asymmetry and the leftward behavioral attentional bias recorded during LBJ task. This correlation was found when LBJ-LI was computed over the hemispheres, in the frontal lobes, but not in the occipital lobes. We then investigated whether language production and spatial attention cerebral lateralization relate to each other, and whether manual preference was a variable that impacted the complementary HS of these functions. No correlation was found between spatial and language LIs in the majority of our sample of participants, including right-handers with a strong right-hand preference (sRH, n=97) and mixed-handers (MH, n=97), indicating that these functions lateralized independently. By contrast, in the group of left-handers with a strong left-hand preference (sLH, n= 99), a negative correlation was found between language and spatial lateralization. This negative correlation was found when LBJ-LI and PROD-LI were computed over the hemispheres, in the frontal lobes and between the occipital lobes for LBJ and the frontal lobes for PROD. These findings underline the importance to include sLH in the study sample to reveal the underlying mechanisms of

Gender and age effects in structural brain asymmetry as measured by MRI texture analysis.

PubMed

Kovalev, Vassili A; Kruggel, Frithjof; von Cramon, D Yves

2003-07-01

Effects of gender and age on structural brain asymmetry were studied by 3D texture analysis in 380 adults. Asymmetry is detected by comparing the complex 3D gray-scale image patterns in the left and right cerebral hemispheres as revealed by anatomical T1-weighted MRI datasets. The Talairach and Tournoux parcellation system was applied to study the asymmetry on five levels: the whole cerebrum, nine coronal sections, 12 axial sections, boxes resulting from both coronal and axial subdivisions, and by a sliding spherical window of 9 mm diameter. The analysis revealed that the brain asymmetry increases in the anterior-posterior direction starting from the central region onward. Male brains were found to be more asymmetric than female. This gender-related effect is noticeable in all brain areas but is most significant in the superior temporal gyrus, Heschl's gyrus, the adjacent white matter regions in the temporal stem and the knee of the optic radiation, the thalamus, and the posterior cingulate. The brain asymmetry increases significantly with age in the inferior frontal gyrus, anterior insula, anterior cingulate, parahippocampal gyrus, retrosplenial cortex, coronal radiata, and knee region of the internal capsule. Asymmetry decreases with age in the optic radiation, precentral gyrus, and angular gyrus. The texture-based method reported here is based on extended multisort cooccurrence matrices that employ intensity, gradient, and anisotropy features in a uniform way. It is sensitive, simple to reproduce, robust, and unbiased in the sense that segmentation of brain compartments and spatial transformations are not necessary. Thus, it should be considered as another tool for digital morphometry in neuroscience.

[Acetabuloplasty in cerebral palsy patients].

PubMed

Schejbalová, A; Chládek, P

2007-12-01

Acetabuloplasty as an isolated surgical procedure is one of the options allowing for hip joint realignment in cerebral palsy patients. Also, it is often involved in combined techniques used for hip joint reconstruction. In the years 2004-2005, 20 cerebral palsy patients, aged from 4 to 13 years, were indicated for acetabuloplasty. The group included children with varying degrees of locomotor disability, ranging from inability even to crawl to ability to move without support (stages 2 to 7 on the Vojta scale). Clinical and X-ray findings were evaluated at 2 and 6 months after surgical treatment and then every 6 months of follow- up. The X-ray finding was described by means of CE angle (Wiberg) values and hip migration percentage. Of 21 hips (in 20 patients) treated by acetabuloplasty in our modification during the two years, one developed recurrent dorsal dislocation which was possible to deal with by conservative treatment. All hips pre-operatively categorized as group B or group C were post-operatively assessed as group A hips. Subsequent migration of the acetabulum occurred within a year in two patients with distinct original asymmetry. Surgery on bones comprising the hip joint in cerebral palsy patients is indicated according to the degree of lateral migration and changes in hip joint geometry involving the proximal femur or pelvis, or in combination with open reduction. Acetabuloplasty is indicated as an isolated procedure or as part of combined techniques leading to a better coverage of the hip joint. It is recommended for children up to 10 years of age, but also older ones, in whom the flexibility of child bones enables us to do without internal osteosynthesis. Acetabuloplasty is indicated as an isolated surgical procedure for hip joint subluxation in cerebral palsy children. It has no adverse effects on hip abductors that, in cerebral palsy patients, are 85 % insufficient. It improves hip joint symmetry and helps to avoid more demanding reconstructive or

From symmetry to asymmetry: Phylogenetic patterns of asymmetry variation in animals and their evolutionary significance

PubMed Central

Palmer, A. Richard

1996-01-01

Phylogenetic analyses of asymmetry variation offer a powerful tool for exploring the interplay between ontogeny and evolution because (i) conspicuous asymmetries exist in many higher metazoans with widely varying modes of development, (ii) patterns of bilateral variation within species may identify genetically and environmentally triggered asymmetries, and (iii) asymmetries arising at different times during development may be more sensitive to internal cytoplasmic inhomogeneities compared to external environmental stimuli. Using four broadly comparable asymmetry states (symmetry, antisymmetry, dextral, and sinistral), and two stages at which asymmetry appears developmentally (larval and postlarval), I evaluated relations between ontogenetic and phylogenetic patterns of asymmetry variation. Among 140 inferred phylogenetic transitions between asymmetry states, recorded from 11 classes in five phyla, directional asymmetry (dextral or sinistral) evolved directly from symmetrical ancestors proportionally more frequently among larval asymmetries. In contrast, antisymmetry, either as an end state or as a transitional stage preceding directional asymmetry, was confined primarily to postlarval asymmetries. The ontogenetic origin of asymmetry thus significantly influences its subsequent evolution. Furthermore, because antisymmetry typically signals an environmentally triggered asymmetry, the phylogenetic transition from antisymmetry to directional asymmetry suggests that many cases of laterally fixed asymmetries evolved via genetic assimilation. PMID:8962039

Structural white matter asymmetries in relation to functional asymmetries during speech perception and production.

PubMed

Ocklenburg, Sebastian; Hugdahl, Kenneth; Westerhausen, René

2013-12-01

Functional hemispheric asymmetries of speech production and perception are a key feature of the human language system, but their neurophysiological basis is still poorly understood. Using a combined fMRI and tract-based spatial statistics approach, we investigated the relation of microstructural asymmetries in language-relevant white matter pathways and functional activation asymmetries during silent verb generation and passive listening to spoken words. Tract-based spatial statistics revealed several leftward asymmetric clusters in the arcuate fasciculus and uncinate fasciculus that were differentially related to activation asymmetries in the two functional tasks. Frontal and temporal activation asymmetries during silent verb generation were positively related to the strength of specific microstructural white matter asymmetries in the arcuate fasciculus. In contrast, microstructural uncinate fasciculus asymmetries were related to temporal activation asymmetries during passive listening. These findings suggest that white matter asymmetries may indeed be one of the factors underlying functional hemispheric asymmetries. Moreover, they also show that specific localized white matter asymmetries might be of greater relevance for functional activation asymmetries than microstructural features of whole pathways. © 2013.

Topographic brain mapping of emotion-related hemisphere asymmetries.

PubMed

Roschmann, R; Wittling, W

1992-03-01

The study used topographic brain mapping of visual evoked potentials to investigate emotion-related hemisphere asymmetries. The stimulus material consisted of color photographs of human faces, grouped into two emotion-related categories: normal faces (neutral stimuli) and faces deformed by dermatological diseases (emotional stimuli). The pictures were presented tachistoscopically to 20 adult right-handed subjects. Brain activity was recorded by 30 EEG electrodes with linked ears as reference. The waveforms were averaged separately with respect to each of the two stimulus conditions. Statistical analysis by means of significance probability mapping revealed significant differences between stimulus conditions for two periods of time, indicating right hemisphere superiority in emotion-related processing. The results are discussed in terms of a 2-stage-model of emotional processing in the cerebral hemispheres.

The Use of Complementary and Alternative Therapies by the Families of Children with Chronic Conditions and Disabilities.

ERIC Educational Resources Information Center

Nickel, Robert E.; Gerlach, Elizabeth King

2001-01-01

This article presents a model for communication among providers and families of children with disabilities about complementary and alternative medicine (CAM). It discusses treatments for children with attention deficit hyperactivity disorder and cerebral palsy, including the Feingold diet, herbal treatments, CranioSacral therapy, therapeutic…

Mood state and cerebral metabolism in persons with age-associated memory impairment.

PubMed

Cherrier, M M; Small, G W; Komo, S; La Rue, A

1997-12-30

People undergoing medical procedures sometimes experience feelings that may influence the results. In this study, we explore the relationship between changes in mood state self-ratings and cerebral glucose metabolism during positron emission tomography (PET) in persons with age-associated memory impairment (mean age 59.4 +/- 9.8 years). Brain regions of interest involved in both mood and memory were examined. Mood ratings of increased boredom correlated significantly with mesial temporal and parietal asymmetry and decreased parietal metabolism. Mood ratings of increased fatigue correlated with basal ganglia asymmetry and the right basal ganglia and left mesial temporal metabolism. These findings suggest that subjective mood state changes during PET may influence metabolism in brain regions implicated in emotion and memory function in people with age-related memory complaints.

The potential role of brain asymmetry in the development of adolescent idiopathic scoliosis: a hypothesis.

PubMed

Niesluchowski, W; Dabrowska, A; Kedzior, K; Zagrajek, T

1999-10-01

The size asymmetry of cerebral hemispheres may predispose to head tilt and asymmetric blocking of the zygapophysial joints, potentially leading to the development of compensatory curvatures in the lower segments of the spine. To analyze the effects of spinal manipulation, maintained by an exercise program, on the progression of idiopathic adolescent scoliosis in 2 children aged 6 and 10. The scoliosis found was 16 and 60 degrees. For diagnosis and monitoring of therapy, we recorded qualitative parameters of shoulder asymmetry, axillary line asymmetry, and scapular angle position. Manual treatment consisted of the examinations of all sliding motion in zygapophysial joints and both sacroiliac joints and removing the limitations of the sliding motions according to the method of Karel Lewit. The treatment procedure consisted of 3 or 4 manipulations within 17 months and an exercise program. The manipulation effects were maintained by the exercise program. The exercises were done in 2 or 3 sessions weekly for a year. In both patients we observed that scoliosis decompensation was successfully stopped and the effects of the correction persisted for 10 years. Brain and head asymmetry may be only a transient state, predisposing to asymmetric blocking at the atlanto-occipital level. Removal of blocking may prevent curve progression in children who had adolescent idiopathic scoliosis. The manipulative therapy may also have a promising effect on retarding curve progression when used in skeletally immature patient.

Spatiotemporal Fractionation Schemes for Irradiating Large Cerebral Arteriovenous Malformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu; Bussière, Marc R.; Chapman, Paul H.

2016-07-01

Purpose: To optimally exploit fractionation effects in the context of radiosurgery treatments of large cerebral arteriovenous malformations (AVMs). In current practice, fractionated treatments divide the dose evenly into several fractions, which generally leads to low obliteration rates. In this work, we investigate the potential benefit of delivering distinct dose distributions in different fractions. Methods and Materials: Five patients with large cerebral AVMs were reviewed and replanned for intensity modulated arc therapy delivered with conventional photon beams. Treatment plans allowing for different dose distributions in all fractions were obtained by performing treatment plan optimization based on the cumulative biologically effective dosemore » delivered at the end of treatment. Results: We show that distinct treatment plans can be designed for different fractions, such that high single-fraction doses are delivered to complementary parts of the AVM. All plans create a similar dose bath in the surrounding normal brain and thereby exploit the fractionation effect. This partial hypofractionation in the AVM along with fractionation in normal brain achieves a net improvement of the therapeutic ratio. We show that a biological dose reduction of approximately 10% in the healthy brain can be achieved compared with reference treatment schedules that deliver the same dose distribution in all fractions. Conclusions: Boosting complementary parts of the target volume in different fractions may provide a therapeutic advantage in fractionated radiosurgery treatments of large cerebral AVMs. The strategy allows for a mean dose reduction in normal brain that may be valuable for a patient population with an otherwise normal life expectancy.« less

Electromagnetically induced transparency (EIT)-like transmission in side-coupled complementary split-ring resonators.

PubMed

Guo, Yinghui; Yan, Lianshan; Pan, Wei; Luo, Bin; Wen, Kunhua; Guo, Zhen; Luo, Xiangang

2012-10-22

We investigate a plasmonic waveguide system based on side-coupled complementary split-ring resonators (CSRR), which exhibits electromagnetically induced transparency (EIT)-like transmission. LC resonance model is utilized to explain the electromagnetic responses of CSRR, which is verified by simulation results of finite difference time domain method. The electromagnetic responses of CSRR can be flexible handled by changing the asymmetry degree of the structure and the width of the metallic baffles. Cascaded CSRRs also have been studied to obtain EIT-like transmission at visible and near-infrared region, simultaneously.

Cerebral lateralization of praxis in right- and left-handedness: same pattern, different strength.

PubMed

Vingerhoets, Guy; Acke, Frederic; Alderweireldt, Ann-Sofie; Nys, Jo; Vandemaele, Pieter; Achten, Eric

2012-04-01

We aimed to investigate the effect of hand effector and handedness on the cerebral lateralization of pantomiming learned movements. Fourteen right-handed and 14 left-handed volunteers performed unimanual and bimanual tool-use pantomimes with their dominant or nondominant hand during fMRI. A left hemispheric lateralization was observed in the right- and left-handed group regardless of which hand(s) performed the task. Asymmetry was most marked in the dorsolateral prefrontal cortex (DLPFC), premotor cortex (PMC), and superior and inferior parietal lobules (SPL and IPL). Unimanual pantomimes did not reveal any significant differences in asymmetric cerebral activation patterns between left- and right-handers. Bimanual pantomimes showed increased left premotor and posterior parietal activation in left- and right-handers. Lateralization indices (LI) of the 10% most active voxels in DLPFC, PMC, SPL, and IPL were calculated for each individual in a contrast that compared all tool versus all control conditions. Left-handers showed a significantly reduced overall LI compared with right-handers. This was mainly due to diminished asymmetry in the IPL and SPL. We conclude that the recollection and pantomiming of learned gestures recruits a similar left lateralized activation pattern in right and left-handed individuals. Handedness only influences the strength (not the side) of the lateralization, with left-handers showing a reduced degree of asymmetry that is most readily observed over the posterior parietal region. Together with similar findings in language and visual processing, these results point to a lesser hemispheric specialization in left-handers that may be considered in the cost/benefit assessment to explain the disproportionate handedness polymorphism in humans. Copyright © 2011 Wiley Periodicals, Inc.

Transcallosal transfer of information and functional asymmetry of the human brain.

PubMed

Nowicka, Anna; Tacikowski, Pawel

2011-01-01

The corpus callosum is the largest commissure in the brain and acts as a "bridge" of nerve fibres connecting the two cerebral hemispheres. It plays a crucial role in interhemispheric integration and is responsible for normal communication and cooperation between the two hemispheres. Evolutionary pressures guiding brain size are accompanied by reduced interhemispheric and enhanced intrahemispheric connectivity. Some lines of evidence suggest that the speed of transcallosal conduction is limited in large brains (e.g., in humans), thus favouring intrahemispheric processing and brain lateralisation. Patterns of directional symmetry/asymmetry of transcallosal transfer time may be related to the degree of brain lateralisation. Neural network modelling and electrophysiological studies on interhemispheric transmission provide data supporting this supposition.

Dengzhanhua preparations for acute cerebral infarction.

PubMed

Cao, Wenzhai; Liu, Weimin; Wu, Taixiang; Zhong, Dechao; Liu, Guanjian

2008-10-08

Dengzhanhua preparations are widely used in China. Many controlled trials have been undertaken to investigate the efficacy of dengzhanhua preparations in the treatment of acute cerebral infarction. To assess whether dengzhanhua preparations are effective and safe at improving outcomes in patients with acute cerebral infarction. We searched the Cochrane Stroke Group Trials Register (last searched October 2007), the Chinese Stroke Trials Register (last searched June 2006), the trials register of the Cochrane Complementary Medicine Field (last searched June 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2 2006), MEDLINE (1966 to June 2006), EMBASE (1980 to June 2006), AMED (the Allied and Complementary Medicine Database, 1985 to June 2006), the China Biological Medicine Database (CBM-disc, 1979 to June 2006), and Chinese Knowledge Infrastructure (CNKI,1994 to October 2007). We also searched the reference lists of relevant articles. Randomised and quasi-randomised controlled clinical trials of dengzhanhua preparations regardless of duration, dosage and route of administration in patients with confirmed acute cerebral infarction. Two review authors independently applied the inclusion criteria, assessed trial quality, and extracted the data. We included nine trials, all conducted in China, involving 723 participants. The method of randomisation and concealment was poorly described. The included trials compared dengzhanhua injection plus routine therapy with routine therapy alone. Patients were enrolled up to one week after the onset of stroke. No trials reported data on the pre-specified primary or secondary outcomes. In a post-hoc comparison of dengzhanhua injection plus routine therapy versus routine therapy alone, dengzhanhua injection showed a statistically significant benefit on the outcome 'marked neurologic improvement' (relative risk 1.53; 95% confidence interval 1.36 to 1.72). No serious adverse effects were

[Cerebral dominance. A study on left-handedness in a Mexican population group].

PubMed

Silva-Rodríguez, A; Escobar-Izquierdo, A

1996-01-01

The term "cerebral dominance" suggests that one hemisphere is leader and the other subordinate; however, cerebral dominance concerning all psychic functions is less frequent than we could suppose. Among the functions in which cerebral dominance is manifested the most notorious is the manual preference. Thus according to the hand being used for general motor activities the persons are named right-handers or left-handers; nevertheless people are less lateralized than we could suppose, and most right-handers may have hidden left-handedness. In order to obtain some data on this subject in Mexican population, a study was done in 300 university students. Of the 275 right-handers only 144 fulfilled the requirements to qualify as such after performing the complementary tests; 25 left-handers came to a mere amount of 5. The data indicate that partial lateralization is more frequent than total lateralization.

Nonlinear Pressure-Flow Relationship Is Able to Detect Asymmetry of Brain Blood Circulation Associated with Midline Shift

PubMed Central

Lo, Men-Tzung; Peng, C.K.; Novak, Vera; Schmidt, Eric A.; Kumar, Ajay; Czosnyka, Marek

2009-01-01

Abstract Reliable and noninvasive assessment of cerebral blood flow regulation is a major challenge in acute care monitoring. This study assessed dynamics of flow regulation and its relationship to asymmetry of initial computed tomography (CT) scan using multimodal pressure flow (MMPF) analysis. Data of 27 patients (38 ± 15 years old) with traumatic brain injury (TBI) were analyzed. Patients were selected from bigger cohort according to criteria of having midline shift on initial CT scan and intact skull (no craniotomy or bone flap). The MMPF analysis was used to extract the oscillations in cerebral perfusion pressure (CPP) and blood flow velocity (BFV) signals at frequency of artificial ventilation, and to calculate the instantaneous phase difference between CPP and BFV oscillations. Mean CPP-BFV phase difference was used to quantify pressure and flow relationship. The TBI subjects had smaller mean BP-BFV phase shifts (left, 8.7 ± 9.6; right 10.2 ± 8.3 MCAs, mean ± SD) than values previously obtained in healthy subjects (left, 37.3 ± 7.6 degrees; right, 38.0 ± 8.9 degrees; p < 0.0001), suggesting impaired blood flow regulation after TBI. The difference in phase shift between CPP and BFV in the left and right side was strongly correlated to the midline shift (R = 0.78; p < 0.0001). These findings indicate that the MMPF method allows reliable assessment of alterations in pressure and flow relationship after TBI. Moreover, mean pressure-flow phase shift is sensitive to the displacement of midline of the brain, and may potentially serve as a marker of asymmetry of cerebral autoregulation. PMID:19196074

Evaluation of cerebral maturation by visual and quantitative analysis of resting electroencephalography in children with primary nocturnal enuresis.

PubMed

Hallioğlu, O; Ozge, A; Comelekoglu, U; Topaloglu, A K; Kanik, A; Duzovali, O; Yilgor, E

2001-10-01

This study was undertaken to evaluate resting electroencephalographic (EEG) changes and their relations to cerebral maturation in children with primary nocturnal enuresis. Cerebral maturation is known to be important in the pathogenesis of this disorder. Twenty-five right-handed patients with primary nocturnal enuresis, aged 6 to 14 years, and 23 age- and sex-matched healthy children were included in this cross-sectional case-control study. The abnormalities detected using such techniques as hemispheral asymmetry, regional differences, and hyperventilation response in addition to visual and quantitative EEG analysis were examined statistically by multivariate analysis. A decrease in alpha activity in the left (dominant hemisphere) temporal lobe and in the frontal lobes bilaterally and an increase in delta activity in the right temporal region were observed. We concluded that insufficient cerebral maturation is an important factor in the pathogenesis of primary nocturnal enuresis, and EEG, as a noninvasive and inexpensive method, could be used in evaluating cerebral maturation.

Detection and quantification of microRNA in cerebral microdialysate.

PubMed

Bache, Søren; Rasmussen, Rune; Rossing, Maria; Hammer, Niels Risør; Juhler, Marianne; Friis-Hansen, Lennart; Nielsen, Finn Cilius; Møller, Kirsten

2015-05-07

Secondary brain injury accounts for a major part of the morbidity and mortality in patients with spontaneous aneurysmal subarachnoid hemorrhage (SAH), but the pathogenesis and pathophysiology remain controversial. MicroRNAs (miRNAs) are important posttranscriptional regulators of complementary mRNA targets and have been implicated in the pathophysiology of other types of acute brain injury. Cerebral microdialysis is a promising tool to investigate these mechanisms. We hypothesized that miRNAs would be present in human cerebral microdialysate. RNA was extracted and miRNA profiles were established using high throughput real-time quantification PCR on the following material: 1) Microdialysate sampled in vitro from A) a solution of total RNA extracted from human brain, B) cerebrospinal fluid (CSF) from a neurologically healthy patient, and C) a patient with SAH; and 2) cerebral microdialysate and CSF sampled in vivo from two patients with SAH. MiRNAs were categorized according to their relative recovery (RR) and a pathway analysis was performed for miRNAs exhibiting a high RR in vivo. Seventy-one of the 160 miRNAs detected in CSF were also found in in vivo microdialysate from SAH patients. Furthermore specific miRNAs consistently exhibited either a high or low RR in both in vitro and in vivo microdialysate. Analysis of repeatability showed lower analytical variation in microdialysate than in CSF. MiRNAs are detectable in cerebral microdialysate; a large group of miRNAs consistently showed a high RR in cerebral microdialysate. Measurement of cerebral interstitial miRNA concentrations may aid in the investigation of secondary brain injury in neurocritical conditions.

Hormone therapy in postmenopausal women affects hemispheric asymmetries in fine motor coordination.

PubMed

Bayer, Ulrike; Hausmann, Markus

2010-08-01

Evidence exists that the functional differences between the left and right cerebral hemispheres are affected by age. One prominent hypothesis proposes that frontal activity during cognitive task performance tends to be less lateralized in older than in younger adults, a pattern that has also been reported for motor functioning. Moreover, functional cerebral asymmetries (FCAs) have been shown to be affected by sex hormonal manipulations via hormone therapy (HT) in older women. Here, we investigate whether FCAs in fine motor coordination, as reflected by manual asymmetries (MAs), are susceptible to HT in older women. Therefore, sixty-two postmenopausal women who received hormone therapy either with estrogen (E) alone (n=15), an E-gestagen combination (n=21) or without HT (control group, n=26) were tested. Saliva levels of free estradiol and progesterone (P) were analyzed using chemiluminescence assays. MAs were measured with a finger tapping paradigm consisting of two different tapping conditions. As expected, postmenopausal controls without HT showed reduced MAs in simple (repetitive) finger tapping. In a more demanding sequential condition involving four fingers, however, they revealed enhanced MAs in favour of the dominant hand. This finding suggests an insufficient recruitment of critical motor brain areas (especially when the nondominant hand is used), probably as a result of age-related changes in corticocortical connectivity between motor areas. In contrast, both HT groups revealed reduced MAs in sequential finger tapping but an asymmetrical tapping performance related to estradiol levels in simple finger tapping. A similar pattern has previously been found in younger participants. The results suggest that, HT, and E exposure in particular, exerts positive effects on the motor system thereby counteracting an age-related reorganization. Copyright 2010 Elsevier Inc. All rights reserved.

Hemisphere Asymmetry of Response to Pharmacologic Treatment in an Alzheimer's Disease Mouse Model.

PubMed

Manousopoulou, Antigoni; Saito, Satoshi; Yamamoto, Yumi; Al-Daghri, Nasser M; Ihara, Masafumi; Carare, Roxana O; Garbis, Spiros D

2016-01-01

The aim of this study was to examine hemisphere asymmetry of response to pharmacologic treatment in an Alzheimer's disease mouse model using cilostazol as a chemical stimulus. Eight-month-old mice were assigned to vehicle or cilostazol treatment for three months and hemispheres were analyzed using quantitative proteomics. Bioinformatics interpretation showed that following treatment, aggregation of blood platelets significantly decreased in the right hemisphere whereas neurodegeneration significantly decreased and synaptic transmission increased in the left hemisphere only. Our study provides novel evidence on cerebral laterality of pharmacologic activity, with important implications in deciphering regional pharmacodynamic effects of existing drugs thus uncovering novel hemisphere-specific therapeutic targets.

Animal left-right asymmetry.

PubMed

Blum, Martin; Ott, Tim

2018-04-02

Symmetry is appealing, be it in architecture, art or facial expression, where symmetry is a key feature to finding someone attractive or not. Yet, asymmetries are widespread in nature, not as an erroneous deviation from the norm but as a way to adapt to the prevailing environmental conditions at a time. Asymmetries in many cases are actively selected for: they might well have increased the evolutionary fitness of a species. Even many single-celled organisms are built asymmetrically, such as the pear-shaped ciliate Paramecium, which may depend on its asymmetry to navigate towards the oxygen-richer surface of turbid waters, at least based on modeling. Everybody knows the lobster with its asymmetric pair of claws, the large crusher usually on the left and the smaller cutter on the right. Snail shells coil asymmetrically, as do the organs they house. Organ asymmetries are found throughout the animal kingdom, referring to asymmetric positioning, asymmetric morphology or both, with the vertebrate heart being an example for the latter. Functional asymmetries, such as that of the human brain with its localization of the language center in one hemisphere, add to the complexity of organ asymmetries and presumably played a decisive role for sociocultural evolution. The evolutionary origin of organ asymmetries may have been a longer than body length gut, which allows efficient retrieval of nutrients, and the need to stow a long gut in the body cavity in an orderly manner that ensures optimal functioning. Vertebrate organ asymmetries (situs solitus) are quite sophisticated: in humans, the apex of the asymmetrically built heart points to the left; the lung in turn, due to space restrictions, has fewer lobes on the left than on the right side (two versus three in humans), stomach and spleen are found on the left, the liver on the right, and small and large intestine coil in a chiral manner (Figure 1A). In very rare cases (1:10,000), the organ situs is inverted (situs inversus

Quantifying asymmetry: ratios and alternatives.

PubMed

Franks, Erin M; Cabo, Luis L

2014-08-01

Traditionally, the study of metric skeletal asymmetry has relied largely on univariate analyses, utilizing ratio transformations when the goal is comparing asymmetries in skeletal elements or populations of dissimilar dimensions. Under this approach, raw asymmetries are divided by a size marker, such as a bilateral average, in an attempt to produce size-free asymmetry indices. Henceforth, this will be referred to as "controlling for size" (see Smith: Curr Anthropol 46 (2005) 249-273). Ratios obtained in this manner often require further transformations to interpret the meaning and sources of asymmetry. This model frequently ignores the fundamental assumption of ratios: the relationship between the variables entered in the ratio must be isometric. Violations of this assumption can obscure existing asymmetries and render spurious results. In this study, we examined the performance of the classic indices in detecting and portraying the asymmetry patterns in four human appendicular bones and explored potential methodological alternatives. Examination of the ratio model revealed that it does not fulfill its intended goals in the bones examined, as the numerator and denominator are independent in all cases. The ratios also introduced strong biases in the comparisons between different elements and variables, generating spurious asymmetry patterns. Multivariate analyses strongly suggest that any transformation to control for overall size or variable range must be conducted before, rather than after, calculating the asymmetries. A combination of exploratory multivariate techniques, such as Principal Components Analysis, and confirmatory linear methods, such as regression and analysis of covariance, appear as a promising and powerful alternative to the use of ratios. © 2014 Wiley Periodicals, Inc.

Asymmetry in the epithalamus of vertebrates

PubMed Central

L. CONCHA, MIGUEL; W. WILSON, STEPHEN

2001-01-01

The epithalamus is a major subdivision of the diencephalon constituted by the habenular nuclei and pineal complex. Structural asymmetries in this region are widespread amongst vertebrates and involve differences in size, neuronal organisation, neurochemistry and connectivity. In species that possess a photoreceptive parapineal organ, this structure projects asymmetrically to the left habenula, and in teleosts it is also situated on the left side of the brain. Asymmetries in size between the left and right sides of the habenula are often associated with asymmetries in neuronal organisation, although these two types of asymmetry follow different evolutionary courses. While the former is more conspicuous in fishes (with the exception of teleosts), asymmetries in neuronal organisation are more robust in amphibia and reptiles. Connectivity of the parapineal organ with the left habenula is not always coupled with asymmetries in habenular size and/or neuronal organisation suggesting that, at least in some species, assignment of parapineal and habenular asymmetries may be independent events. The evolutionary origins of epithalamic structures are uncertain but asymmetry in this region is likely to have existed at the origin of the vertebrate, perhaps even the chordate, lineage. In at least some extant vertebrate species, epithalamic asymmetries are established early in development, suggesting a genetic regulation of asymmetry. In some cases, epigenetic factors such as hormones also influence the development of sexually dimorphic habenular asymmetries. Although the genetic and developmental mechanisms by which neuroanatomical asymmetries are established remain obscure, some clues regarding the mechanisms underlying laterality decisions have recently come from studies in zebrafish. The Nodal signalling pathway regulates laterality by biasing an otherwise stochastic laterality decision to the left side of the epithalamus. This genetic mechanism ensures a consistency of

Asymmetry and coherence weight of quantum states

NASA Astrophysics Data System (ADS)

Bu, Kaifeng; Anand, Namit; Singh, Uttam

2018-03-01

The asymmetry of quantum states is an important resource in quantum information processing tasks such as quantum metrology and quantum communication. In this paper, we introduce the notion of asymmetry weight—an operationally motivated asymmetry quantifier in the resource theory of asymmetry. We study the convexity and monotonicity properties of asymmetry weight and focus on its interplay with the corresponding semidefinite programming (SDP) forms along with its connection to other asymmetry measures. Since the SDP form of asymmetry weight is closely related to asymmetry witnesses, we find that the asymmetry weight can be regarded as a (state-dependent) asymmetry witness. Moreover, some specific entanglement witnesses can be viewed as a special case of an asymmetry witness—which indicates a potential connection between asymmetry and entanglement. We also provide an operationally meaningful coherence measure, which we term coherence weight, and investigate its relationship to other coherence measures like the robustness of coherence and the l1 norm of coherence. In particular, we show that for Werner states in any dimension d all three coherence quantifiers, namely, the coherence weight, the robustness of coherence, and the l1 norm of coherence, are equal and are given by a single letter formula.

MRI of plaque characteristics and relationship with downstream perfusion and cerebral infarction in patients with symptomatic middle cerebral artery stenosis.

PubMed

Lu, Shan-Shan; Ge, Song; Su, Chun-Qiu; Xie, Jun; Mao, Jian; Shi, Hai-Bin; Hong, Xun-Ning

2017-10-30

perfusion impairment. Plaque enhancement and perfusion evaluation may play a complementary role to luminal stenosis in determining the occurrence of acute cerebral infarction. 4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

Endocranial shape asymmetries in Pan paniscus, Pan troglodytes and Gorilla gorilla assessed via skull based landmark analysis.

PubMed

Balzeau, Antoine; Gilissen, Emmanuel

2010-07-01

Brain shape asymmetries or petalias consist of the extension of one cerebral hemisphere beyond the other. A larger frontal or caudal projection is usually coupled with a larger lateral extent of the more projecting hemisphere relative to the other. The concurrence of these petalial components is characteristic of hominins. Studies aimed at quantifying petalial asymmetries in human and great ape endocasts rely on the definition of the midline of the endocranial surface. Studies of brain material show that, at least in humans, most of the medial surface of the left occipital lobe distorts along the midline and protrudes on to the right side, making it difficult for midline and corresponding left and right reference point identification. In order to accurately quantify and compare brain shape asymmetries in extant hominid species, we propose here a new protocol based on the objective definition of cranial landmarks. We describe and quantify for the first time in three dimensions the positions of frontal and occipital protrusions in large samples of Pan paniscus, Pan troglodytes and Gorilla gorilla. This study confirms the existence of frontal and occipital petalias in African apes. Moreover, the detailed analysis of the 3D structure of these petalias reveals shared features, as well as features that are unique to the different great ape species.

Asymmetries in motor attention during a cued bimanual reaching task: left and right handers compared.

PubMed

Buckingham, Gavin; Main, Julie C; Carey, David P

2011-04-01

Several studies have indicated that right handers have attention biased toward their right hand during bimanual coordination (Buckingham and Carey, 2009; Peters, 1981). To determine if this behavioral asymmetry was linked to cerebral lateralization, we examined this bias in left and right handers by combining a discontinuous double-step reaching task with a Posner-style hand cueing paradigm. Left and right handed participants received a tactile cue (valid on 80% of trials) prior to a bimanual reach to target pairs. Right handers took longer to inhibit their right hand and made more right hand errors, suggesting that their dominant hand was more readily primed to move than their non-dominant hand, likely due to the aforementioned attentional bias. Left handers, however, showed neither of these asymmetries, suggesting that they lack an equivalent dominant hand attentional bias. The findings are discussed in relation to recent unimanual handedness tasks in right and left handers, and the lateralization of systems for speech, language and motor attention. Copyright © 2009. Published by Elsevier Srl.

Improvements in muscle symmetry in children with cerebral palsy after equine-assisted therapy (hippotherapy).

PubMed

Benda, William; McGibbon, Nancy H; Grant, Kathryn L

2003-12-01

To evaluate the effect of hippotherapy (physical therapy utilizing the movement of a horse) on muscle activity in children with spastic cerebral palsy. Pretest/post-test control group. Therapeutic Riding of Tucson (TROT), Tucson, AZ. Fifteen (15) children ranging from 4 to 12 years of age diagnosed with spastic cerebral palsy. Children meeting inclusion criteria were randomized to either 8 minutes of hippotherapy or 8 minutes astride a stationary barrel. Remote surface electromyography (EMG) was used to measure muscle activity of the trunk and upper legs during sitting, standing, and walking tasks before and after each intervention. After hippotherapy, significant improvement in symmetry of muscle activity was noted in those muscle groups displaying the highest asymmetry prior to hippotherapy. No significant change was noted after sitting astride a barrel. Eight minutes of hippotherapy, but not stationary sitting astride a barrel, resulted in improved symmetry in muscle activity in children with spastic cerebral palsy. These results suggest that the movement of the horse rather than passive stretching accounts for the measured improvements.

Selected Gray Matter Volumes and Gender but Not Basal Ganglia nor Cerebellum Gyri Discriminate Left Versus Right Cerebral Hemispheres: Multivariate Analyses in human Brains at 3T.

PubMed

Roldan-Valadez, Ernesto; Suarez-May, Marcela A; Favila, Rafael; Aguilar-Castañeda, Erika; Rios, Camilo

2015-07-01

Interest in the lateralization of the human brain is evident through a multidisciplinary number of scientific studies. Understanding volumetric brain asymmetries allows the distinction between normal development stages and behavior, as well as brain diseases. We aimed to evaluate volumetric asymmetries in order to select the best gyri able to classify right- versus left cerebral hemispheres. A cross-sectional study performed in 47 right-handed young-adults healthy volunteers. SPM-based software performed brain segmentation, automatic labeling and volumetric analyses for 54 regions involving the cerebral lobes, basal ganglia and cerebellum from each cerebral hemisphere. Multivariate discriminant analysis (DA) allowed the assembling of a predictive model. DA revealed one discriminant function that significantly differentiated left vs. right cerebral hemispheres: Wilks' λ = 0.008, χ(2) (9) = 238.837, P < 0.001. The model explained 99.20% of the variation in the grouping variable and depicted an overall predictive accuracy of 98.8%. With the influence of gender; the selected gyri able to discriminate between hemispheres were middle orbital frontal gyrus (g.), angular g., supramarginal g., middle cingulum g., inferior orbital frontal g., calcarine g., inferior parietal lobule and the pars triangularis inferior frontal g. Specific brain gyri are able to accurately classify left vs. right cerebral hemispheres by using a multivariate approach; the selected regions correspond to key brain areas involved in attention, internal thought, vision and language; our findings favored the concept that lateralization has been evolutionary favored by mental processes increasing cognitive efficiency and brain capacity. © 2015 Wiley Periodicals, Inc.

Fetal cerebral imaging - ultrasound vs. MRI: an update.

PubMed

Blondiaux, Eléonore; Garel, Catherine

2013-11-01

The purpose of this article is to analyze the advantages and limitations of prenatal ultrasonography (US) and magnetic resonance imaging (MRI) in the evaluation of the fetal brain. These imaging modalities should not be seen as competitive but rather as complementary. There are wide variations in the world regarding screening policies, technology, skills, and legislation about termination of pregnancy, and these variations markedly impact on the way of using prenatal imaging. According to the contribution expected from each technique and to local working conditions, one should choose the most appropriate imaging modality on a case-by-case basis. The advantages and limitations of US and MRI in the setting of fetal brain imaging are displayed. Different anatomical regions (midline, ventricles, subependymal area, cerebral parenchyma, pericerebral space, posterior fossa) and pathological conditions are analyzed and illustrated in order to compare the respective contribution of each technique. An accurate prenatal diagnosis of cerebral abnormalities is of utmost importance for prenatal counseling.

Intrachromosomal karyotype asymmetry in Orchidaceae.

PubMed

Medeiros-Neto, Enoque; Nollet, Felipe; Moraes, Ana Paula; Felix, Leonardo P

2017-01-01

The asymmetry indexes have helped cytotaxonomists to interpret and classify plant karyotypes for species delimitation efforts. However, there is no consensus about the best method to calculate the intrachromosomal asymmetry. The present study aimed to compare different intrachromosomal asymmetry indexes in order to indicate which are more efficient for the estimation of asymmetry in different groups of orchids. Besides, we aimed to compare our results with the Orchidaceae phylogenetic proposal to test the hypothesis of Stebbins (1971). Through a literature review, karyotypes were selected and analyzed comparatively with ideal karyotypes in a cluster analysis. All karyotypes showed some level of interchromosomal asymmetry, ranging from slightly asymmetric to moderately asymmetric. The five tested intrachromosomal asymmetry indexes indicated Sarcoglottis grandiflora as the species with the most symmetrical karyotype and Christensonella pachyphylla with the most asymmetrical karyotype. In the cluster analysis, the largest number of species were grouped with the intermediary ideal karyotypes B or C. Considering our results, we recommend the combined use of at least two indexes, especially Ask% or A1 with Syi, for cytotaxonomic analysis in groups of orchids. In an evolutionary perspective, our results support Stebbins' hypothesis that asymmetric karyotypes derive from a symmetric karyotypes.

[Diagnosis of facial and craniofacial asymmetry].

PubMed

Arnaud, E; Marchac, D; Renier, D

2001-10-01

Craniofacial asymmetry is caused by various aetiologies but clinical examination remains the most important criteria since minor asymmetry is always present. The diagnosis can be confirmed by anthropometric measurements and radiological examinations but only severe asymmetries or asymmetries with an associated functional impairment should be treated. The treatment depends on the cause, and on the time of appearance. Congenital asymmetries might be treated early, during the first year of life if a craniosynostosis is present. Hemifacial microsomia are treated later if there is no breathing impairment. Since the pediatricians have recommended the dorsal position for infant sleeping, an increasing number of posterior flattening of the skull has been appearing, and could be prevented by adequate nursing. Other causes of craniofacial asymmetries are rare and should be adapted to the cause (tumors, atrophies, neurological paralysis, hypertrophies) by a specialized multidisciplinar team.

Assessing and conceptualizing frontal EEG asymmetry: An updated primer on recording, processing, analyzing, and interpreting frontal alpha asymmetry.

PubMed

Smith, Ezra E; Reznik, Samantha J; Stewart, Jennifer L; Allen, John J B

2017-01-01

Frontal electroencephalographic (EEG) alpha asymmetry is widely researched in studies of emotion, motivation, and psychopathology, yet it is a metric that has been quantified and analyzed using diverse procedures, and diversity in procedures muddles cross-study interpretation. The aim of this article is to provide an updated tutorial for EEG alpha asymmetry recording, processing, analysis, and interpretation, with an eye towards improving consistency of results across studies. First, a brief background in alpha asymmetry findings is provided. Then, some guidelines for recording, processing, and analyzing alpha asymmetry are presented with an emphasis on the creation of asymmetry scores, referencing choices, and artifact removal. Processing steps are explained in detail, and references to MATLAB-based toolboxes that are helpful for creating and investigating alpha asymmetry are noted. Then, conceptual challenges and interpretative issues are reviewed, including a discussion of alpha asymmetry as a mediator/moderator of emotion and psychopathology. Finally, the effects of two automated component-based artifact correction algorithms-MARA and ADJUST-on frontal alpha asymmetry are evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

Dichotic listening in patients with situs inversus: brain asymmetry and situs asymmetry.

PubMed

Tanaka, S; Kanzaki, R; Yoshibayashi, M; Kamiya, T; Sugishita, M

1999-06-01

In order to investigate the relation between situs asymmetry and functional asymmetry of the human brain, a consonant-vowel syllable dichotic listening test known as the Standard Dichotic Listening Test (SDLT) was administered to nine subjects with situs inversus (SI) that ranged in age from 6 to 46 years old (mean of 21.8 years old, S.D. = 15.6); the four males and five females all exhibited strong right-handedness. The SDLT was also used to study twenty four age-matched normal subjects that were from 6 to 48 years old (mean 21.7 years old, S.D. = 15.3); the twelve males and twelve females were all strongly right-handed and served as a control group. Eight out of the nine subjects (88.9%) with SI more often reproduced the sounds from the right ear than sounds from the left ear; this is called right ear advantage (REA). The ratio of REA in the control group was almost the same, i.e., nineteen out of the twenty-four subjects (79.1%) showed REA. Results of the present study suggest that the left-right reversal in situs inversus does not involve functional asymmetry of the brain. As such, the system that produces functional asymmetry in the human brain must independently recognize laterality from situs asymmetry.

Complementary medicine.

PubMed Central

Spiegel, D; Stroud, P; Fyfe, A

1998-01-01

The widespread use of complementary and alternative medicine techniques, often explored by patients without discussion with their primary care physician, is seen as a request from patients for care as well as cure. In this article, we discuss the reasons for the growth of and interest in complementary and alternative medicine in an era of rapidly advancing medical technology. There is, for instance, evidence of the efficacy of supportive techniques such as group psychotherapy in improving adjustment and increasing survival time of cancer patients. We describe current and developing complementary medicine programs as well as opportunities for integration of some complementary techniques into standard medical care. PMID:9584661

Black–white asymmetry in visual perception

PubMed Central

Lu, Zhong-Lin; Sperling, George

2012-01-01

With eleven different types of stimuli that exercise a wide gamut of spatial and temporal visual processes, negative perturbations from mean luminance are found to be typically 25% more effective visually than positive perturbations of the same magnitude (range 8–67%). In Experiment 12, the magnitude of the black–white asymmetry is shown to be a saturating function of stimulus contrast. Experiment 13 shows black–white asymmetry primarily involves a nonlinearity in the visual representation of decrements. Black–white asymmetry in early visual processing produces even-harmonic distortion frequencies in all ordinary stimuli and in illusions such as the perceived asymmetry of optically perfect sine wave gratings. In stimuli intended to stimulate exclusively second-order processing in which motion or shape are defined not by luminance differences but by differences in texture contrast, the black–white asymmetry typically generates artifactual luminance (first-order) motion and shape components. Because black–white asymmetry pervades psychophysical and neurophysiological procedures that utilize spatial or temporal variations of luminance, it frequently needs to be considered in the design and evaluation of experiments that involve visual stimuli. Simple procedures to compensate for black–white asymmetry are proposed. PMID:22984221

Intrachromosomal karyotype asymmetry in Orchidaceae

PubMed Central

Medeiros-Neto, Enoque; Nollet, Felipe; Moraes, Ana Paula; Felix, Leonardo P.

2017-01-01

Abstract The asymmetry indexes have helped cytotaxonomists to interpret and classify plant karyotypes for species delimitation efforts. However, there is no consensus about the best method to calculate the intrachromosomal asymmetry. The present study aimed to compare different intrachromosomal asymmetry indexes in order to indicate which are more efficient for the estimation of asymmetry in different groups of orchids. Besides, we aimed to compare our results with the Orchidaceae phylogenetic proposal to test the hypothesis of Stebbins (1971). Through a literature review, karyotypes were selected and analyzed comparatively with ideal karyotypes in a cluster analysis. All karyotypes showed some level of interchromosomal asymmetry, ranging from slightly asymmetric to moderately asymmetric. The five tested intrachromosomal asymmetry indexes indicated Sarcoglottis grandiflora as the species with the most symmetrical karyotype and Christensonella pachyphylla with the most asymmetrical karyotype. In the cluster analysis, the largest number of species were grouped with the intermediary ideal karyotypes B or C. Considering our results, we recommend the combined use of at least two indexes, especially Ask% or A1 with Syi, for cytotaxonomic analysis in groups of orchids. In an evolutionary perspective, our results support Stebbins’ hypothesis that asymmetric karyotypes derive from a symmetric karyotypes. PMID:28644507

Bilateral asymmetry prediction.

PubMed

Kostoff, Ronald Neil

2003-08-01

This study predicts asymmetries in lateral organ cancer incidence from text mining of the Medline database. Lung, kidney, teste, and ovary cancers were examined. For each cancer, Medline case report articles focused solely on (1) cancer of the right organ and (2) cancer of the left organ were retrieved. The ratio of right organ to left organ articles was compared to actual patient incidence data obtained from the National Cancer Institute's (NCI) SEER database for the period 1979-1998. The agreement between the Medline record ratios and the NCI's patient incidence data ratios ranged from within 3% for lung cancer to within 1% for teste and ovary cancer. This is the first known study to generate cancer lateral incidence asymmetries from the Medline database. The technique should be applicable to other diseases and other types of system asymmetries.

Fluctuating Asymmetry and Intelligence

ERIC Educational Resources Information Center

Bates, Timothy C.

2007-01-01

The general factor of mental ability ("g") may reflect general biological fitness. If so, "g"-loaded measures such as Raven's progressive matrices should be related to morphological measures of fitness such as fluctuating asymmetry (FA: left-right asymmetry of a set of typically left-right symmetrical body traits such as finger…

Asymmetries of solar oscillation line profiles

NASA Technical Reports Server (NTRS)

Duvall, T. L., Jr.; Jefferies, S. M.; Harvey, J. W.; Osaki, Y.; Pomerantz, M. A.

1993-01-01

Asymmetries of the power spectral line profiles of solar global p-modes are detected in full-disk intensity observations of the Ca II K Fraunhofer line. The asymmetry is a strong function of temporal frequency being strongest at the lowest frequencies observed and vanishing near the peak of the power distribution. The variation with spherical harmonic degree is small. The asymmetry is interpreted in terms of a model in which the solar oscillation cavity is compared to a Fabry-Perot interferometer with the source slightly outside the cavity. A phase difference between an outward direct wave and a corresponding inward wave that passes through the cavity gives rise to the asymmetry. The asymmetry is different in velocity and intensity observations. Neglecting the asymmetry when modeling the power spectrum can lead to systematic errors in the measurement of mode frequencies of as much as 10 exp -4 of the mode frequency. The present observations and interpretation locate the source of the oscillations to be approximately 60 km beneath the photosphere, the shallowest position suggested to date.

``Green's function'' approach & low-mode asymmetries

NASA Astrophysics Data System (ADS)

Masse, Laurent; Clark, Dan; Salmonson, Jay; MacLaren, Steve; Ma, Tammy; Khan, Shahab; Pino, Jesse; Ralph, Jo; Czajka, C.; Tipton, Robert; Landen, Otto; Kyrala, Georges; 2 Team; 1 Team

2017-10-01

Long wavelength, low mode asymmetries are believed to play a leading role in limiting the performance of current ICF implosions on NIF. These long wavelength modes are initiated and driven by asymmetries in the x-ray flux from the hohlraum; however, the underlying hydrodynamics of the implosion also act to amplify these asymmetries. The work presented here aim to deepen our understanding of the interplay of the drive asymmetries and the underlying implosion hydrodynamics in determining the final imploded configuration. This is accomplished through a synthesis of numerical modeling, analytic theory, and experimental data. In detail, we use a Green's function approach to connect the drive asymmetry seen by the capsule to the measured inflight and hot spot symmetries. The approach has been validated against a suite of numerical simulations. Ultimately, we hope this work will identify additional measurements to further constrain the asymmetries and increase hohlraum illumination design flexibility on the NIF. The technique and derivation of associated error bars will be presented. LLC, (LLNS) Contract No. DE-AC52-07NA27344.

Bilateral Asymmetry in the Human Pelvis.

PubMed

Kurki, Helen K

2017-04-01

Asymmetry of the human axial skeleton has received much less attention that of the limb skeleton. Pelvic morphology is subject to multiple selective factors, including bipedal locomotion and obstetrics, among others, as well as environmental factors such as biomechanical loading. How these various factors influence or restrict asymmetry of the pelvis is unknown and few studies have investigated levels and patterns of pelvic asymmetry. This study examines percentage directional (%DA) and absolute (%AA) asymmetry in 14 bilaterally paired dimensions of the pelvic canal, non-canal pelvis, and femur in female (n = 111) and male (n = 126) skeletons from nine geographically dispersed skeletal samples. Directional asymmetries were uniformly low for all measures and lacked any consistent patterning across the variables, while %AA was highest in the pelvic canal, particularly the posterior aspects. Few sex differences and no population differences were found for %DA and %AA; however the latter was correlated with coefficients of variation across the 14 variables in both sexes. While sample mean %DA were low, standard deviations of the canal variables were high and the majority of individuals in both sexes displayed %DA values >±0.5, suggesting asymmetry is common, if not directionally consistent. Biomechanical loading of the pelvic girdle may influence asymmetry of both the canal and non-canal aspects of the pelvis; however it is unlikely that these asymmetries negatively affect obstetric function, given the prevalence for %DA found in this study. Anat Rec, 300:653-665, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Complementary functions of the two brain hemispheres: comparisons with earlier conceptions and implications for individual and society.

PubMed

Zeier, H

1989-07-01

The concept of different functions for the left and right cerebral hemispheres coincides in an astonishing way with earlier philosophical and psychological work which divided the human mind into two complementary functions without having a neurophysiological explanation. Representative are the ideas of Fichte, Hegel and Jung. The latter postulated the two subsystems Ego and Self and associated the conscious functions of the Ego with the intellect, the capacity for rational thought, and the Self with the mind, which also includes the emotional feelings. For the harmonic development and self-realization of man the functions of both systems in complementary interaction are required. Therefore, the current overaccentuation of the intellect and of progress directed technical-scientific thinking should be corrected by making better use of the much neglected functions of the right hemisphere.

Compensation procedures for facial asymmetries.

PubMed

Kozol, F

1995-01-01

Why would a patient complain of "fuzzy and uncomfortable" vision with a variety of glasses? Perhaps because the practitioner has failed to take facial asymmetry into account. Methods of measuring facial asymmetry and optically correcting for it are discussed.

Analytical formulation of lunar cratering asymmetries

NASA Astrophysics Data System (ADS)

Wang, Nan; Zhou, Ji-Lin

2016-10-01

Context. The cratering asymmetry of a bombarded satellite is related to both its orbit and impactors. The inner solar system impactor populations, that is, the main-belt asteroids (MBAs) and the near-Earth objects (NEOs), have dominated during the late heavy bombardment (LHB) and ever since, respectively. Aims: We formulate the lunar cratering distribution and verify the cratering asymmetries generated by the MBAs as well as the NEOs. Methods: Based on a planar model that excludes the terrestrial and lunar gravitations on the impactors and assuming the impactor encounter speed with Earth venc is higher than the lunar orbital speed vM, we rigorously integrated the lunar cratering distribution, and derived its approximation to the first order of vM/venc. Numerical simulations of lunar bombardment by the MBAs during the LHB were performed with an Earth-Moon distance aM = 20-60 Earth radii in five cases. Results: The analytical model directly proves the existence of a leading/trailing asymmetry and the absence of near/far asymmetry. The approximate form of the leading/trailing asymmetry is (1 + A1cosβ), which decreases as the apex distance β increases. The numerical simulations show evidence of a pole/equator asymmetry as well as the leading/trailing asymmetry, and the former is empirically described as (1 + A2cos2ϕ), which decreases as the latitude modulus | ϕ | increases. The amplitudes A1,2 are reliable measurements of asymmetries. Our analysis explicitly indicates the quantitative relations between cratering distribution and bombardment conditions (impactor properties and the lunar orbital status) like A1 ∝ vM/venc, resulting in a method for reproducing the bombardment conditions through measuring the asymmetry. Mutual confirmation between analytical model and numerical simulations is found in terms of the cratering distribution and its variation with aM. Estimates of A1 for crater density distributions generated by the MBAs and the NEOs are 0.101-0.159 and 0

Toroidal current asymmetry in tokamak disruptions

NASA Astrophysics Data System (ADS)

Strauss, H. R.

2014-10-01

It was discovered on JET that disruptions were accompanied by toroidal asymmetry of the toroidal plasma current I ϕ. It was found that the toroidal current asymmetry was proportional to the vertical current moment asymmetry with positive sign for an upward vertical displacement event (VDE) and negative sign for a downward VDE. It was observed that greater displacement leads to greater measured I ϕ asymmetry. Here, it is shown that this is essentially a kinematic effect produced by a VDE interacting with three dimensional MHD perturbations. The relation of toroidal current asymmetry and vertical current moment is calculated analytically and is verified by numerical simulations. It is shown analytically that the toroidal variation of the toroidal plasma current is accompanied by an equal and opposite variation of the toroidal current flowing in a thin wall surrounding the plasma. These currents are connected by 3D halo current, which is π/2 radians out of phase with the n = 1 toroidal current variations.

A voxel-based asymmetry study of the relationship between hemispheric asymmetry and language dominance in Wada tested patients.

PubMed

Keller, Simon S; Roberts, Neil; Baker, Gus; Sluming, Vanessa; Cezayirli, Enis; Mayes, Andrew; Eldridge, Paul; Marson, Anthony G; Wieshmann, Udo C

2018-03-23

Determining the anatomical basis of hemispheric language dominance (HLD) remains an important scientific endeavor. The Wada test remains the gold standard test for HLD and provides a unique opportunity to determine the relationship between HLD and hemispheric structural asymmetries on MRI. In this study, we applied a whole-brain voxel-based asymmetry (VBA) approach to determine the relationship between interhemispheric structural asymmetries and HLD in a large consecutive sample of Wada tested patients. Of 135 patients, 114 (84.4%) had left HLD, 10 (7.4%) right HLD, and 11 (8.2%) bilateral language representation. Fifty-four controls were also studied. Right-handed controls and right-handed patients with left HLD had comparable structural brain asymmetries in cortical, subcortical, and cerebellar regions that have previously been documented in healthy people. However, these patients and controls differed in structural asymmetry of the mesial temporal lobe and a circumscribed region in the superior temporal gyrus, suggesting that only asymmetries of these regions were due to brain alterations caused by epilepsy. Additional comparisons between patients with left and right HLD, matched for type and location of epilepsy, revealed that structural asymmetries of insula, pars triangularis, inferior temporal gyrus, orbitofrontal cortex, ventral temporo-occipital cortex, mesial somatosensory cortex, and mesial cerebellum were significantly associated with the side of HLD. Patients with right HLD and bilateral language representation were significantly less right-handed. These results suggest that structural asymmetries of an insular-fronto-temporal network may be related to HLD. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Asymmetry in search.

PubMed

Kaindl, H; Kainz, G; Radda, K

2001-01-01

Most of the work on search in artificial intelligence (AI) deals with one search direction only-mostly forward search-although it is known that a structural asymmetry of the search graph causes differences in the efficiency of searching in the forward or the backward direction, respectively. In the case of symmetrical graph structure, however, current theory would not predict such differences in efficiency. In several classes of job sequencing problems, we observed a phenomenon of asymmetry in search that relates to the distribution of the are costs in the search graph. This phenomenon can be utilized for improving the search efficiency by a new algorithm that automatically selects the search direction. We demonstrate fur a class of job sequencing problems that, through the utilization of this phenomenon, much more difficult problems can be solved-according to our best knowledge-than by the best published approach, and on the same problems, the running time is much reduced. As a consequence, we propose to check given problems for asymmetrical distribution of are costs that may cause asymmetry in search.

Mapping hemispheric symmetries, relative asymmetries, and absolute asymmetries underlying the auditory laterality effect.

PubMed

Westerhausen, René; Kompus, Kristiina; Hugdahl, Kenneth

2014-01-01

Functional hemispheric differences for speech and language processing have been traditionally studied by using verbal dichotic-listening paradigms. The commonly observed right-ear preference for the report of dichotically presented syllables is taken to reflect the left hemispheric dominance for speech processing. However, the results of recent functional imaging studies also show that both hemispheres - not only the left - are engaged by dichotic listening, suggesting a more complex relationship between behavioral laterality and functional hemispheric activation asymmetries. In order to more closely examine the hemispheric differences underlying dichotic-listening performance, we report an analysis of functional magnetic resonance imaging (fMRI) data of 104 right-handed subjects, for the first time combining an interhemispheric difference and conjunction analysis. This approach allowed for a distinction of homotopic brain regions which showed symmetrical (i.e., brain region significantly activated in both hemispheres and no activation difference between the hemispheres), relative asymmetrical (i.e., activated in both hemispheres but significantly stronger in one than the other hemisphere), and absolute asymmetrical activation patterns (i.e., activated only in one hemisphere and this activation is significantly stronger than in the other hemisphere). Symmetrical activation was found in large clusters encompassing temporal, parietal, inferior frontal, and medial superior frontal regions. Relative and absolute left-ward asymmetries were found in the posterior superior temporal gyrus, located adjacent to symmetrically activated areas, and creating a lateral-medial gradient from symmetrical towards absolute asymmetrical activation within the peri-Sylvian region. Absolute leftward asymmetry was also found in the post-central and medial superior frontal gyri, while rightward asymmetries were found in middle temporal and middle frontal gyri. We conclude that dichotic

Movement asymmetry in working polo horses.

PubMed

Pfau, T; Parkes, R S; Burden, E R; Bell, N; Fairhurst, H; Witte, T H

2016-07-01

The high, repetitive demands imposed on polo horses in training and competition may predispose them to musculoskeletal injuries and lameness. To quantify movement symmetry and lameness in a population of polo horses, and to investigate the existence of a relationship with age. Convenience sampled cross-sectional study. Sixty polo horses were equipped with inertial measurement units (IMUs) attached to the poll, and between the tubera sacrale. Six movement symmetry measures were calculated for vertical head and pelvic displacement during in-hand trot and compared with values for perfect symmetry, compared between left and right limb lame horses, and compared with published thresholds for lameness. Regression lines were calculated as a function of age of horse. Based on 2 different sets of published asymmetry thresholds 52-53% of the horses were quantified with head movement asymmetry and 27-50% with pelvic movement asymmetry resulting in 60-67% of horses being classified with movement asymmetry outside published guideline values for either the forelimbs, hindlimbs or both. Neither forelimb nor hindlimb asymmetries were preferentially left or right sided, with directional asymmetry values across all horses not different from perfect symmetry and absolute values not different between left and right lame horses (P values >0.6 for all forelimb symmetry measures and >0.2 for all hindlimb symmetry measures). None of the symmetry parameters increased or decreased significantly with age. A large proportion of polo horses show gait asymmetries consistent with previously defined thresholds for lameness. These do not appear to be lateralised or associated with age. © 2015 EVJ Ltd.

[Orthodontic treatment of Class III patients with mandibular asymmetry].

PubMed

Duan, Yin-Zhong; Huo, Na; Chen, Lei; Chen, Xue-Peng; Lin, Yang

2008-12-01

To investigate the treatment outcome of Class III patients with dental, functional and mild skeletal mandibular asymmetry. Thirty-five patients (14 males and 21 females) with dental, functional and mild skeletal mandibular asymmetry were selected. The age range of the patients was 7 - 22 years with a mean age of 16.5 years. Dental mandibular asymmetry was treated with expansion of maxillary arch to help the mandible returning to normal position. Functional mandibular asymmetry was treated with activator or asymmetrical protraction and Class III elastics. Mild skeletal mandibular asymmetry was treated with camouflage treatment. Good occlusal relationships were achieved and facial esthetics was greatly improved after orthodontic treatment in patients with dental and functional mandibular asymmetry. However, patients with skeletal mandibular asymmetry should be treated with both extraction and genioplasty. Orthodontic treatment was suitable for patients with dental and functional mandibular asymmetry, while combined orthodontics and surgery could get good results in patients with skeletal mandibular asymmetry.

Estimation of land-surface evaporation at four forest sites across Japan with the new nonlinear complementary method.

PubMed

Ai, Zhipin; Wang, Qinxue; Yang, Yonghui; Manevski, Kiril; Zhao, Xin; Eer, Deni

2017-12-19

Evaporation from land surfaces is a critical component of the Earth water cycle and of water management strategies. The complementary method originally proposed by Bouchet, which describes a linear relation between actual evaporation (E), potential evaporation (E po ) and apparent potential evaporation (E pa ) based on routinely measured weather data, is one of the various methods for evaporation calculation. This study evaluated the reformulated version of the original method, as proposed by Brutsaert, for forest land cover in Japan. The new complementary method is nonlinear and based on boundary conditions with strictly physical considerations. The only unknown parameter (α e ) was for the first time determined for various forest covers located from north to south across Japan. The values of α e ranged from 0.94 to 1.10, with a mean value of 1.01. Furthermore, the calculated evaporation with the new method showed a good fit with the eddy-covariance measured values, with a determination coefficient of 0.78 and a mean bias of 4%. Evaluation results revealed that the new nonlinear complementary relation performs better than the original linear relation in describing the relationship between E/E pa and E po /E pa , and also in depicting the asymmetry variation between E pa /E po and E/E po .

Human cerebral potentials evoked by moving dynamic random dot stereograms.

PubMed

Herpers, M J; Caberg, H B; Mol, J M

1981-07-01

In 11 normal healthy human subjects an evoked potential was elicited by moving dynamic random dot stereograms. The random dots were generated by a minicomputer. An average of each of 8 EEG channels of the subjects tested was made. The maximum of the cerebral evoked potentials thus found was localized in the central and parietal region. No response earlier than 130--150 msec after the stimulus could be proved. The influence of fixation, the number of dots provided, an interocular interstimulus interval in the presentation of the dots, and lense accommodation movements on the evoked stereoptic potentials was investigated and discussed. An interocular interstimulus interval (left eye leading) in the presentation of the dots caused an increase in latency of the response much longer than the imposed interstimulus interval itself. It was shown that no accommodation was needed to perceive the depth impression, and to evoke the cerebral response with random dot stereograms. There are indications of an asymmetry between the two hemispheres in the handling of depth perception after 250 msec. The potential distribution of the evoked potentials strongly suggests that they are not generated in the occipital region.

The Inherent Asymmetry of DNA Replication.

PubMed

Snedeker, Jonathan; Wooten, Matthew; Chen, Xin

2017-10-06

Semiconservative DNA replication has provided an elegant solution to the fundamental problem of how life is able to proliferate in a way that allows cells, organisms, and populations to survive and replicate many times over. Somewhat lost, however, in our admiration for this mechanism is an appreciation for the asymmetries that occur in the process of DNA replication. As we discuss in this review, these asymmetries arise as a consequence of the structure of the DNA molecule and the enzymatic mechanism of DNA synthesis. Increasing evidence suggests that asymmetries in DNA replication are able to play a central role in the processes of adaptation and evolution by shaping the mutagenic landscape of cells. Additionally, in eukaryotes, recent work has demonstrated that the inherent asymmetries in DNA replication may play an important role in the process of chromatin replication. As chromatin plays an essential role in defining cell identity, asymmetries generated during the process of DNA replication may play critical roles in cell fate decisions related to patterning and development.

Poloidal asymmetries in edge transport barriersa)

NASA Astrophysics Data System (ADS)

Churchill, R. M.; Theiler, C.; Lipschultz, B.; Hutchinson, I. H.; Reinke, M. L.; Whyte, D.; Hughes, J. W.; Catto, P.; Landreman, M.; Ernst, D.; Chang, C. S.; Hager, R.; Hubbard, A.; Ennever, P.; Walk, J. R.

2015-05-01

Measurements of impurities in Alcator C-Mod indicate that in the pedestal region, significant poloidal asymmetries can exist in the impurity density, ion temperature, and main ion density. In light of the observation that ion temperature and electrostatic potential are not constant on a flux surface [Theiler et al., Nucl. Fusion 54, 083017 (2014)], a technique based on total pressure conservation to align profiles measured at separate poloidal locations is presented and applied. Gyrokinetic neoclassical simulations with XGCa support the observed large poloidal variations in ion temperature and density, and that the total pressure is approximately constant on a flux surface. With the updated alignment technique, the observed in-out asymmetry in impurity density is reduced from previous publishing [Churchill et al., Nucl. Fusion 53, 122002 (2013)], but remains substantial ( n z , H / n z , L ˜ 6 ). Candidate asymmetry drivers are explored, showing that neither non-uniform impurity sources nor localized fluctuation-driven transport are able to explain satisfactorily the impurity density asymmetry. Since impurity density asymmetries are only present in plasmas with strong electron density gradients, and radial transport timescales become comparable to parallel transport timescales in the pedestal region, it is suggested that global transport effects relating to the strong electron density gradients in the pedestal are the main driver for the pedestal in-out impurity density asymmetry.

TMD evolution of the Sivers asymmetry

NASA Astrophysics Data System (ADS)

Boer, Daniël

2013-09-01

The energy scale dependence of the Sivers asymmetry in semi-inclusive deep inelastic scattering is studied numerically within the framework of TMD factorization that was put forward in 2011. The comparison to previous results in the literature shows that the treatment of next-to-leading logarithmic effects is important for the fall-off of the Sivers asymmetry with energy in the measurable regime. The TMD factorization based approach indicates that the peak of the Sivers asymmetry falls off with energy scale Q to good approximation as 1/Q0.7, somewhat faster than found previously based on the first TMD factorization expressions by Collins and Soper in 1981. It is found that the peak of the asymmetry moves rather slowly towards higher transverse momentum values as Q increases, which may be due to the absence of perturbative tails of the TMDs in the presented treatments. We conclude that the behavior of the peak of the asymmetry as a function of energy and transverse momentum allows for valuable tests of the TMD formalism and the considered approximations. To confront the TMD approach with experiment, high energy experimental data from an Electron-Ion Collider is required. Note that in B01/B09 the Gaussian width of the Sivers TMD appears in the asymmetry expressions, because of the derivative in f1T⊥ ' a(x;Q0).

Exchange asymmetry in experimental settings

Treesearch

Thomas C. Brown; Mark D. Morrison; Jacob A. Benfield; Gretchen Nurse Rainbolt; Paul A. Bell

2015-01-01

We review past trading experiments and present 11 new experiments designed to show how the trading rate responds to alterations of the experimental procedure. In agreement with earlier studies, results show that if the trade decision is converted to one resembling a choice between goods the exchange asymmetry disappears, but otherwise the asymmetry is...

Nodal signalling and asymmetry of the nervous system

PubMed Central

Signore, Iskra A.; Palma, Karina

2016-01-01

The role of Nodal signalling in nervous system asymmetry is still poorly understood. Here, we review and discuss how asymmetric Nodal signalling controls the ontogeny of nervous system asymmetry using a comparative developmental perspective. A detailed analysis of asymmetry in ascidians and fishes reveals a critical context-dependency of Nodal function and emphasizes that bilaterally paired and midline-unpaired structures/organs behave as different entities. We propose a conceptual framework to dissect the developmental function of Nodal as asymmetry inducer and laterality modulator in the nervous system, which can be used to study other types of body and visceral organ asymmetries. Using insights from developmental biology, we also present novel evolutionary hypotheses on how Nodal led the evolution of directional asymmetry in the brain, with a particular focus on the epithalamus. We intend this paper to provide a synthesis on how Nodal signalling controls left–right asymmetry of the nervous system. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821531

Permeability Asymmetry in Composite Porous Ceramic Membranes

NASA Astrophysics Data System (ADS)

Kurcharov, I. M.; Laguntsov, N. I.; Uvarov, V. I.; Kurchatova, O. V.

The results from the investigation of transport characteristics and gas transport asymmetry in bilayer composite membranes are submitted. These membranes are produced by SHS method. Asymmetric effect and hysteresis of permeability in nanoporous membranes are detected. It's shown, that permeability ratio (asymmetry value of permeability) increases up to several times. The asymmetry of permeability usually decreases monotonically with the pressure decrease.

Bessel Weighted Asymmetries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avakian, Harut; Gamberg, Leonard; Rossi, Patrizia

We review the concept of Bessel weighted asymmetries for semi-inclusive deep inelastic scattering and focus on the cross section in Fourier space, conjugate to the outgoing hadron’s transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. The procedure is applied to studies of the double longitudinal spin asymmetry in semi-inclusive deep inelastic scattering using a new dedicated Monte Carlo generator which includes quark intrinsic transverse momentum within the generalized partonmore » model. We observe a few percent systematic offset of the Bessel-weighted asymmetry obtained from Monte Carlo extraction compared to input model calculations, which is due to the limitations imposed by the energy and momentum conservation at the given energy and hard scale Q2. We find that the Bessel weighting technique provides a powerful and reliable tool to study the Fourier transform of TMDs with controlled systematics due to experimental acceptances and resolutions with different TMD model inputs.« less

Validity and sensitivity of the longitudinal asymmetry index to detect gait asymmetry using Microsoft Kinect data.

PubMed

Auvinet, E; Multon, F; Manning, V; Meunier, J; Cobb, J P

2017-01-01

Gait asymmetry information is a key point in disease screening and follow-up. Constant Relative Phase (CRP) has been used to quantify within-stride asymmetry index, which requires noise-free and accurate motion capture, which is difficult to obtain in clinical settings. This study explores a new index, the Longitudinal Asymmetry Index (ILong) which is derived using data from a low-cost depth camera (Kinect). ILong is based on depth images averaged over several gait cycles, rather than derived joint positions or angles. This study aims to evaluate (1) the validity of CRP computed with Kinect, (2) the validity and sensitivity of ILong for measuring gait asymmetry based solely on data provided by a depth camera, (3) the clinical applicability of a posteriorly mounted camera system to avoid occlusion caused by the standard front-fitted treadmill consoles and (4) the number of strides needed to reliably calculate ILong. The gait of 15 subjects was recorded concurrently with a marker-based system (MBS) and Kinect, and asymmetry was artificially reproduced by introducing a 5cm sole attached to one foot. CRP computed with Kinect was not reliable. ILong detected this disturbed gait reliably and could be computed from a posteriorly placed Kinect without loss of validity. A minimum of five strides was needed to achieve a correlation coefficient of 0.9 between standard MBS and low-cost depth camera based ILong. ILong provides a clinically pragmatic method for measuring gait asymmetry, with application for improved patient care through enhanced disease, screening, diagnosis and monitoring. Copyright © 2016. Published by Elsevier B.V.

Management of delayed cerebral ischemia after subarachnoid hemorrhage.

PubMed

Koenig, Matthew A

2012-06-01

The purpose of this article is to describe the modern management of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (SAH). SAH causes an inflammatory reaction to blood products in the basal cisterns of the brain, which may produce cerebral ischemia and strokes through progressive narrowing of the cerebral artery lumen. This process, known as cerebral vasospasm, is the most common cause of DCI after SAH. Untreated DCI may result in strokes, which account for a significant portion of the death and long-term disability after SAH. A number of publications, including two recent consensus statements, have clarified many best practices for defining, diagnosing, monitoring, preventing, and treating DCI. DCI is best defined as new onset of focal or global neurologic deficits or strokes not attributable to another cause. In addition to the clinical examination, radiographic studies such as transcranial Doppler ultrasonography, CT angiography, and CT perfusion may have a role in determining which patients are at high risk for developing DCI. The mainstay of prevention and treatment of DCI is maintenance of euvolemia, which can be a difficult therapeutic target to measure. Hemodynamic augmentation with induced hypertension with or without inotropic support has become the first-line treatment of DCI. The ideal method of measuring hemodynamic values and volume status in patients with DCI remains elusive. In patients who do not adequately respond to or cannot tolerate hemodynamic augmentation, endovascular therapy (intraarterial vasodilators and balloon angioplasty) is a complementary strategy. Optimal triggers for escalation and de-escalation of therapies for DCI have not been well defined. Recent guidelines and consensus statements have clarified many aspects of prevention, monitoring, and treatment of DCI after SAH. Controversies continue regarding the optimal methods for measurement of volume status, the role of invasive neuromonitoring

New human-specific brain landmark: the depth asymmetry of superior temporal sulcus.

PubMed

Leroy, François; Cai, Qing; Bogart, Stephanie L; Dubois, Jessica; Coulon, Olivier; Monzalvo, Karla; Fischer, Clara; Glasel, Hervé; Van der Haegen, Lise; Bénézit, Audrey; Lin, Ching-Po; Kennedy, David N; Ihara, Aya S; Hertz-Pannier, Lucie; Moutard, Marie-Laure; Poupon, Cyril; Brysbaert, Marc; Roberts, Neil; Hopkins, William D; Mangin, Jean-François; Dehaene-Lambertz, Ghislaine

2015-01-27

Identifying potentially unique features of the human cerebral cortex is a first step to understanding how evolution has shaped the brain in our species. By analyzing MR images obtained from 177 humans and 73 chimpanzees, we observed a human-specific asymmetry in the superior temporal sulcus at the heart of the communication regions and which we have named the "superior temporal asymmetrical pit" (STAP). This 45-mm-long segment ventral to Heschl's gyrus is deeper in the right hemisphere than in the left in 95% of typical human subjects, from infanthood till adulthood, and is present, irrespective of handedness, language lateralization, and sex although it is greater in males than in females. The STAP also is seen in several groups of atypical subjects including persons with situs inversus, autistic spectrum disorder, Turner syndrome, and corpus callosum agenesis. It is explained in part by the larger number of sulcal interruptions in the left than in the right hemisphere. Its early presence in the infants of this study as well as in fetuses and premature infants suggests a strong genetic influence. Because this asymmetry is barely visible in chimpanzees, we recommend the STAP region during midgestation as an important phenotype to investigate asymmetrical variations of gene expression among the primate lineage. This genetic target may provide important insights regarding the evolution of the crucial cognitive abilities sustained by this sulcus in our species, namely communication and social cognition.

Facial Asymmetry: Brow and Ear Position.

PubMed

Perumal, Balaji; Meyer, Dale R

2018-04-01

The purpose of the current study was to analyze brow and ear position, and examine the relationship between these structures in patients presenting for blepharoplasty evaluation. A retrospective chart review was performed, which included all patients presenting to one oculoplastic physician for a blepharoplasty evaluation from November, 2012 to March, 2014. The prevalence of brow ptosis and brow and ear asymmetry was calculated; the proportional distribution was determined, and chi-square analysis and the z-test of proportions were used to calculate the significance. Institutional Review Board approval was obtained for this study. A total of 133 patients met the inclusion criteria. Some degree of brow ptosis was noted in 83% of patients. Brow asymmetry was found in 88% of patients, and ear asymmetry in 77%. Of those patients who had asymmetry, 61% had the right brow lower and 75% had the right ear lower; 73% of all patients had the brow and ear lower on the same side ( p  < 0.001). In this study, brow ptosis and asymmetry were quite common. In addition, the side of the lower brow correlated strongly with the side of the lower ear, and the right side structures were lower more often than the left. Patients presenting for blepharoplasty evaluation may have an element of generalized facial asymmetry which includes the brows and ears. These observations can be important for preoperative planning and patient counseling. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Asymmetry identification in rigid rotating bodies—Theory and experiment

NASA Astrophysics Data System (ADS)

Bucher, Izhak; Shomer, Ofer

2013-12-01

Asymmetry and anisotropy are important parameters in rotating devices that can cause instability; indicate a manufacturing defect or a developing fault. The present paper discusses an identification method capable of detecting minute levels of asymmetry by exploiting the unique dynamics of parametric excitation caused by asymmetry and rotation. The detection relies on rigid body dynamics without resorting to nonlinear vibration analysis, and the natural dynamics of elastically supported systems is exploited in order to increase the sensitivity to asymmetry. It is possible to isolate asymmetry from other rotation-induced phenomena like unbalance. An asymmetry detection machine which was built in the laboratory demonstrates the method alongside theoretical analysis.

Charging-induced asymmetry in molecular conductors

NASA Astrophysics Data System (ADS)

Zahid, F.; Ghosh, A. W.; Paulsson, M.; Polizzi, E.; Datta, S.

2004-12-01

We investigate the origin of asymmetry in various measured current-voltage (I-V) characteristics of molecules with no inherent spatial asymmetry, with particular focus on a recent break junction measurement. We argue that such asymmetry arises due to unequal coupling with the contacts and a consequent difference in charging effects, which can only be captured in a self-consistent model for molecular conduction. The direction of the asymmetry depends on the sign of the majority carriers in the molecule. For conduction through highest occupied molecular orbitals (i.e., HOMO or p -type conduction), the current is smaller for positive voltage on the stronger contact, while for conduction through lowest unoccupied molecular orbitals (i.e., LUMO or n -type conduction), the sense of the asymmetry is reversed. Within an extended Hückel description of the molecular chemistry and the contact microstructure (with two adjustable parameters, the position of the Fermi energy and the sulphur-gold bond length), an appropriate description of Poisson’s equation, and a self-consistently coupled nonequilibrium Green’s function description of transport, we achieve good agreement between theoretical and experimental I-V characteristics, both in shape as well as overall magnitude.

Induced static asymmetry of the pelvis is associated with functional asymmetry of the lumbo-pelvo-hip complex.

PubMed

Gnat, Rafał; Saulicz, Edward

2008-03-01

This study evaluates the hypothesis that triggering and eliminating induced static pelvic asymmetry (SPA) may be followed by immediate change in functional asymmetry of the lumbo-pelvo-hip complex. Repeated measures experimental design with 2 levels of independent variable, that is, induced SPA triggered and induced SPA eliminated, was implemented. Three series of measurements were performed, that is, baseline, after triggering SPA, and after eliminating SPA. A group of 84 subjects with no initial symptoms of SPA was studied. Different forms of mechanical stimulation were applied aiming to induce SPA, and the 2 manual stretching-manipulating techniques were performed aiming to eliminate it. A hand inclinometer was used to measure SPA in standing posture. Selected ranges of motion of the hip joints and lumbar spine were used to depict functional asymmetry of the lumbo-pelvo-hip complex. The functional asymmetry indices for individual movements were calculated. Repeated measures design of analysis of variance, dependent data Student t test, and linear Pearson's correlation test were used. Assessment of the SPA showed its significant increase between baseline and series 2 measurements, with a subsequent significant decrease between series 2 and series 3 measurements. Values of the functional asymmetry indices changed accordingly, that is, they increased significantly between series 1 and series 2 and had returned to their initial level in series 3 measurements. Induced SPA shows considerable association with functional asymmetry of the lumbo-pelvo-hip complex.

Autophoretic locomotion from geometric asymmetry.

PubMed

Michelin, Sébastien; Lauga, Eric

2015-02-01

Among the few methods which have been proposed to create small-scale swimmers, those relying on self-phoretic mechanisms present an interesting design challenge in that chemical gradients are required to generate net propulsion. Building on recent work, we propose that asymmetries in geometry are sufficient to induce chemical gradients and swimming. We illustrate this idea using two different calculations. We first calculate exactly the self-propulsion speed of a system composed of two spheres of unequal sizes but identically chemically homogeneous. We then consider arbitrary, small-amplitude, shape deformations of a chemically homogeneous sphere, and calculate asymptotically the self-propulsion velocity induced by the shape asymmetries. Our results demonstrate how geometric asymmetries can be tuned to induce large locomotion speeds without the need of chemical patterning.

Prevalence of arytenoid asymmetry in relation to vocal symptoms.

PubMed

Hamdan, A-L; Nassar, J; Ashkar, J; Sibai, A

2011-03-01

(1) To assess the prevalence of arytenoid asymmetry during adduction, and (2) to correlate arytenoid asymmetry with vocal symptoms. The medical records and video recordings of 116 patients who presented to the voice clinic were reviewed for the presence of arytenoid asymmetry, as regards sharpening of the aryepiglottic fold angle and altered positioning of the cuneiform and corniculate cartilages. There were 61 males and 55 females, with a mean age of 39 years and a standard deviation of 15 years. Almost one-third had a history of reflux, 25 per cent had a history of smoking and 9.6 per cent had a history of allergy. Hoarseness was the most common symptom, occurring in 42.2 per cent of patients, followed by vocal fatigue (25 per cent) and inability to project the voice. The most common type of asymmetry was corniculate asymmetry, present in 27.6 per cent of the cases and accounting for 74.39 per cent of cases. This was followed by cuneiform cartilage asymmetry, present in 15.5 per cent of cases. There was no correlation between arytenoid asymmetry and vocal symptoms, except for vocal fatigue (p = 0.038). The prevalence of arytenoid asymmetry during adduction is common. The presence of vocal symptoms such as hoarseness, breathiness, inability to project the voice and straining does not generally seem to correlate with the prevalence of arytenoid asymmetry. However, subjects with vocal fatigue are more likely to have cuneiform asymmetry.

Hemispheric asymmetries in dorsal language pathway white-matter tracts: A magnetic resonance imaging tractography and functional magnetic resonance imaging study.

PubMed

Silva, Guilherme; Citterio, Alberto

2017-10-01

Introduction Previous studies have shown that the arcuate fasciculus has a leftward asymmetry in right-handers that could be correlated with the language lateralisation defined by functional magnetic resonance imaging. Nonetheless, information about the asymmetry of the other fibres that constitute the dorsal language pathway is scarce. Objectives This study investigated the asymmetry of the white-matter tracts involved in the dorsal language pathway through the diffusion tensor imaging (DTI) technique, in relation to language hemispheric dominance determined by task-dependent functional magnetic resonance imaging (fMRI). Methods We selected 11 patients (10 right-handed) who had been studied with task-dependent fMRI for language areas and DTI and who had no language impairment or structural abnormalities that could compromise magnetic resonance tractography of the fibres involved in the dorsal language pathway. Laterality indices (LI) for fMRI and for the volumes of each tract were calculated. Results In fMRI, all the right-handers had left hemispheric lateralisation, and the ambidextrous subject presented right hemispheric dominance. The arcuate fasciculus LI was strongly correlated with fMRI LI ( r = 0.739, p = 0.009), presenting the same lateralisation of fMRI in seven subjects (including the right hemispheric dominant). It was not asymmetric in three cases and had opposite lateralisation in one case. The other tracts presented predominance for rightward lateralisation, especially superior longitudinal fasciculus (SLF) II/III (nine subjects), but their LI did not correlate (directly or inversely) with fMRI LI. Conclusion The fibres that constitute the dorsal language pathway have an asymmetric distribution in the cerebral hemispheres. Only the asymmetry of the arcuate fasciculus is correlated with fMRI language lateralisation.

Quantum asymmetry between time and space

PubMed Central

2016-01-01

An asymmetry exists between time and space in the sense that physical systems inevitably evolve over time, whereas there is no corresponding ubiquitous translation over space. The asymmetry, which is presumed to be elemental, is represented by equations of motion and conservation laws that operate differently over time and space. If, however, the asymmetry was found to be due to deeper causes, this conventional view of time evolution would need reworking. Here we show, using a sum-over-paths formalism, that a violation of time reversal (T) symmetry might be such a cause. If T symmetry is obeyed, then the formalism treats time and space symmetrically such that states of matter are localized both in space and in time. In this case, equations of motion and conservation laws are undefined or inapplicable. However, if T symmetry is violated, then the same sum over paths formalism yields states that are localized in space and distributed without bound over time, creating an asymmetry between time and space. Moreover, the states satisfy an equation of motion (the Schrödinger equation) and conservation laws apply. This suggests that the time–space asymmetry is not elemental as currently presumed, and that T violation may have a deep connection with time evolution. PMID:26997899

Anomalies and asymmetries in quark-gluon matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teryaev, O. V., E-mail: teryaev@theor.jinr.ru

The manifestations of axial anomaly and related effects in heavy-ion collisions are considered. Special role is played by various asymmetries. The azimuthal correlational asymmetries of neutron pairs at NICA/FAIR energy range may probe the global rotation of strongly interacting matter. The conductivity is related to the angular asymmetries of dilepton pairs. The strong magnetic field generated in heavy-ion collisions leads to the excess of soft dileptons flying predominantly in the scattering plane.

Geometric asymmetry driven Janus micromotors

NASA Astrophysics Data System (ADS)

Zhao, Guanjia; Pumera, Martin

2014-09-01

The production and application of nano-/micromotors is of great importance. In order for the motors to work, asymmetry in their chemical composition or physical geometry must be present if no external asymmetric field is applied. In this paper, we present a ``coconut'' micromotor made of platinum through the partial or complete etching of the silica templates. It was shown that although both the inner and outer surfaces are made of the same material (Pt), motion of the structure can be observed as the convex surface is capable of generating oxygen bubbles. This finding shows that not only the chemical asymmetry of the micromotor, but also its geometric asymmetry can lead to fast propulsion of the motor. Moreover, a considerably higher velocity can be seen for partially etched coconut structures than the velocities of Janus or fully etched, shell-like motors. These findings will have great importance on the design of future micromotors.The production and application of nano-/micromotors is of great importance. In order for the motors to work, asymmetry in their chemical composition or physical geometry must be present if no external asymmetric field is applied. In this paper, we present a ``coconut'' micromotor made of platinum through the partial or complete etching of the silica templates. It was shown that although both the inner and outer surfaces are made of the same material (Pt), motion of the structure can be observed as the convex surface is capable of generating oxygen bubbles. This finding shows that not only the chemical asymmetry of the micromotor, but also its geometric asymmetry can lead to fast propulsion of the motor. Moreover, a considerably higher velocity can be seen for partially etched coconut structures than the velocities of Janus or fully etched, shell-like motors. These findings will have great importance on the design of future micromotors. Electronic supplementary information (ESI) available: Additional SEM images, data analysis, Videos S

Introduction to provocative questions in left-right asymmetry.

PubMed

Levin, Michael; Klar, Amar J S; Ramsdell, Ann F

2016-12-19

Left-right asymmetry is a phenomenon that has a broad appeal-to anatomists, developmental biologists and evolutionary biologists-because it is a morphological feature of organisms that spans scales of size and levels of organization, from unicellular protists, to vertebrate organs, to social behaviour. Here, we highlight a number of important aspects of asymmetry that encompass several areas of biology-cell-level, physiological, genetic, anatomical and evolutionary components-and that are based on research conducted in diverse model systems, ranging from single cells to invertebrates to human developmental disorders. Together, the contributions in this issue reveal a heretofore-unsuspected variety in asymmetry mechanisms, including ancient chirality elements that could underlie a much more universal basis to asymmetry development, and provide much fodder for thought with far reaching implications in biomedical, developmental, evolutionary and synthetic biology. The new emerging theme of binary cell-fate choice, promoted by asymmetric cell division of a deterministic cell, has focused on investigating asymmetry mechanisms functioning at the single cell level. These include cytoskeleton and DNA chain asymmetry-mechanisms that are amplified and coordinated with those employed for the determination of the anterior-posterior and dorsal-ventral axes of the embryo.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

Characterization of Atrophic Changes in the Cerebral Cortex Using Fractal Dimensional Analysis

PubMed Central

George, Anuh T.; Jeon, Tina; Hynan, Linda S.; Youn, Teddy S.; Kennedy, David N.; Dickerson, Bradford

2010-01-01

The purpose of this project is to apply a modified fractal analysis technique to high-resolution T1 weighted magnetic resonance images in order to quantify the alterations in the shape of the cerebral cortex that occur in patients with Alzheimer’s disease. Images were selected from the Alzheimer’s Disease Neuroimaging Initiative database (Control N=15, Mild-Moderate AD N=15). The images were segmented using a semi-automated analysis program. Four coronal and three axial profiles of the cerebral cortical ribbon were created. The fractal dimensions (Df) of the cortical ribbons were then computed using a box-counting algorithm. The mean Df of the cortical ribbons from AD patients were lower than age-matched controls on six of seven profiles. The fractal measure has regional variability which reflects local differences in brain structure. Fractal dimension is complementary to volumetric measures and may assist in identifying disease state or disease progression. PMID:20740072

Three-dimensional assessment of facial asymmetry: A systematic review.

PubMed

Akhil, Gopi; Senthil Kumar, Kullampalayam Palanisamy; Raja, Subramani; Janardhanan, Kumaresan

2015-08-01

For patients with facial asymmetry, complete and precise diagnosis, and surgical treatments to correct the underlying cause of the asymmetry are significant. Conventional diagnostic radiographs (submento-vertex projections, posteroanterior radiography) have limitations in asymmetry diagnosis due to two-dimensional assessments of three-dimensional (3D) images. The advent of 3D images has greatly reduced the magnification and projection errors that are common in conventional radiographs making it as a precise diagnostic aid for assessment of facial asymmetry. Thus, this article attempts to review the newly introduced 3D tools in the diagnosis of more complex facial asymmetries.

Entanglement asymmetry for boosted black branes and the bound

NASA Astrophysics Data System (ADS)

Mishra, Rohit; Singh, Harvendra

2017-06-01

We study the effects of asymmetry in the entanglement thermodynamics of CFT subsystems. It is found that “boosted” Dp-brane backgrounds give rise to the first law of the entanglement thermodynamics where the CFT pressure asymmetry plays a decisive role in the entanglement. Two different strip like subsystems, one parallel to the boost and the other perpendicular, are studied in the perturbative regime Tthermal ≪ TE. We mainly seek to quantify this entanglement asymmetry as a ratio of the first-order entanglement entropies of the excitations. We discuss the AdS-wave backgrounds at zero temperature having maximum asymmetry from where a bound on entanglement asymmetry is obtained. The entanglement asymmetry reduces as we switch on finite temperature in the CFT while it is maximum at zero temperature.

Regional facial asymmetries and attractiveness of the face.

PubMed

Kaipainen, Anu E; Sieber, Kevin R; Nada, Rania M; Maal, Thomas J; Katsaros, Christos; Fudalej, Piotr S

2016-12-01

Facial attractiveness is an important factor in our social interactions. It is still not entirely clear which factors influence the attractiveness of a face and facial asymmetry appears to play a certain role. The aim of the present study was to assess the association between facial attractiveness and regional facial asymmetries evaluated on three-dimensional (3D) images. 3D facial images of 59 (23 male, 36 female) young adult patients (age 16-25 years) before orthodontic treatment were evaluated for asymmetry. The same 3D images were presented to 12 lay judges who rated the attractiveness of each subject on a 100mm visual analogue scale. Reliability of the method was assessed with Bland-Altman plots and Cronbach's alpha coefficient. All subjects showed a certain amount of asymmetry in all regions of the face; most asymmetry was found in the chin and cheek areas and less in the lip, nose and forehead areas. No statistically significant differences in regional facial asymmetries were found between male and female subjects (P > 0.05). Regression analyses demonstrated that the judgement of facial attractiveness was not influenced by absolute regional facial asymmetries when gender, facial width-to-height ratio and type of malocclusion were controlled (P > 0.05). A potential limitation of the study could be that other biologic and cultural factors influencing the perception of facial attractiveness were not controlled for. A small amount of asymmetry was present in all subjects assessed in this study, and asymmetry of this magnitude may not influence the assessment of facial attractiveness. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Measurement of parity-violating asymmetry in electron-deuteron inelastic scattering

DOE PAGES

Wang, D.; Pan, K.; Subedi, R.; ...

2015-04-01

The parity-violating asymmetries between a longitudinally-polarized electron beam and an unpolarized deuterium target have been measured recently. The measurement covered two kinematic points in the deep inelastic scattering region and five in the nucleon resonance region. We provide here details of the experimental setup, data analysis, and results on all asymmetry measurements including parity-violating electron asymmetries and those of inclusive pion production and beam-normal asymmetries. The parity-violating deep-inelastic asymmetries were used to extract the electron-quark weak effective couplings, and the resonance asymmetries provided the first evidence for quark-hadron duality in electroweak observables. These electron asymmetries and their interpretation were publishedmore » earlier, but are presented here in more detail.« less

Mercury exposure may influence fluctuating asymmetry in waterbirds

USGS Publications Warehouse

Herring, Garth; Eagles-Smith, Collin A.; Ackerman, Joshua T.

2017-01-01

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds.

Asymmetry of the Brain: Development and Implications.

PubMed

Duboc, Véronique; Dufourcq, Pascale; Blader, Patrick; Roussigné, Myriam

2015-01-01

Although the left and right hemispheres of our brains develop with a high degree of symmetry at both the anatomical and functional levels, it has become clear that subtle structural differences exist between the two sides and that each is dominant in processing specific cognitive tasks. As the result of evolutionary conservation or convergence, lateralization of the brain is found in both vertebrates and invertebrates, suggesting that it provides significant fitness for animal life. This widespread feature of hemispheric specialization has allowed the emergence of model systems to study its development and, in some cases, to link anatomical asymmetries to brain function and behavior. Here, we present some of what is known about brain asymmetry in humans and model organisms as well as what is known about the impact of environmental and genetic factors on brain asymmetry development. We specifically highlight the progress made in understanding the development of epithalamic asymmetries in zebrafish and how this model provides an exciting opportunity to address brain asymmetry at different levels of complexity.

Quantifying cerebral asymmetries for language in dextrals and adextrals with random-effects meta analysis

PubMed Central

Carey, David P.; Johnstone, Leah T.

2014-01-01

Speech and language-related functions tend to depend on the left hemisphere more than the right in most right-handed (dextral) participants. This relationship is less clear in non-right handed (adextral) people, resulting in surprisingly polarized opinion on whether or not they are as lateralized as right handers. The present analysis investigates this issue by largely ignoring methodological differences between the different neuroscientific approaches to language lateralization, as well as discrepancies in how dextral and adextral participants were recruited or defined. Here we evaluate the tendency for dextrals to be more left hemisphere dominant than adextrals, using random effects meta analyses. In spite of several limitations, including sample size (in the adextrals in particular), missing details on proportions of groups who show directional effects in many experiments, and so on, the different paradigms all point to proportionally increased left hemispheric dominance in the dextrals. These results are analyzed in light of the theoretical importance of these subtle differences for understanding the cognitive neuroscience of language, as well as the unusual asymmetry in most adextrals. PMID:25408673

Fluctuating asymmetry and stress in a medieval Nubian population.

PubMed

Deleon, Valerie B

2007-04-01

Fluctuating asymmetry is commonly used as a bioindicator of developmental stress. This study addresses asymmetry under nutritional/systemic stress in the human craniofacial skeleton and its utility as an indicator of developmental instability. Crania from the diachronic Christian cemeteries at Kulubnarti (Sudanese Nubia) were chosen as a model for nutrition/systemic stress. Previous studies indicate that individuals from the Early Christian cemetery were subjected to greater developmental stress when compared with individuals from the Late Christian cemetery. Therefore, crania from the Early Christian cemetery should display a greater magnitude of fluctuating asymmetry than crania from the Late Christian cemetery. Thirty adult crania of comparable age and sex were selected from each population. Landmark coordinates were digitized in two separate trials and averaged to minimize error. Euclidean distance matrix analysis (EDMA) was used to measure and compare the magnitude of fluctuating asymmetry in each sample. Results indicate that crania from the Early Christian cemetery display greater amounts of fluctuating asymmetry than those from the Late Christian cemetery, as predicted. The degree of fluctuating asymmetry for each linear distance is highly correlated between the cemeteries, suggesting that all humans may share common patterns of fluctuating asymmetry in the skull. In contrast, there is little correlation between magnitude of fluctuating asymmetry and length of linear distance, between-subject variability, or measurement error. These results support the hypothesis that poor nutrition/systemic stress increases developmental instability in the human skull and that increased fluctuating asymmetry constitutes morphological evidence of this stress.

Transverse single-spin asymmetries: Challenges and recent progress

DOE PAGES

Metz, Andreas; Pitonyak, Daniel; Schafer, Andreas; ...

2014-11-25

In this study, transverse single-spin asymmetries are among the most intriguing observables in hadronic physics. Though such asymmetries were already measured for the first time about four decades ago, their origin is still under debate. Here we consider transverse single-spin asymmetries in semi-inclusive lepton–nucleon scattering, in nucleon–nucleon scattering, and in inclusive lepton–nucleon scattering. It is argued that, according to recent work, the single-spin asymmetries for those three processes may be simultaneously described in perturbative QCD, where the re-scattering of the active partons plays a crucial role. A comparison of single-spin asymmetries in different reactions can also shed light on themore » universality of transverse momentum dependent parton correlation functions. In particular, we discuss what existing data may tell us about the predicted process dependence of the Sivers function.« less

Cerebral aneurysm

MedlinePlus Videos and Cool Tools

The tissue of the brain is supplied by a network of cerebral arteries. If the wall of a cerebral artery becomes weakened, a portion of the wall may balloon out forming an aneurysm. A cerebral aneurysm may enlarge until it bursts, sending blood ...

Effects of longitudinal asymmetry in heavy-ion collisions

NASA Astrophysics Data System (ADS)

Raniwala, Rashmi; Raniwala, Sudhir; Loizides, Constantin

2018-02-01

In collisions of identical nuclei at a given impact parameter, the number of nucleons participating in the overlap region of each nucleus can be unequal due to nuclear density fluctuations. The asymmetry due to the unequal number of participating nucleons, referred to as longitudinal asymmetry, causes a shift in the center-of-mass rapidity of the participant zone. The information of the event asymmetry allows us to isolate and study the effect of longitudinal asymmetry on rapidity distribution of final state particles. In a Monte Carlo Glauber model the average rapidity shift is found to be almost linearly related to the asymmetry. Using toy models, as well as Monte Carlo data for Pb-Pb collisions at 2.76 TeV generated with hijing, two different versions of ampt and dpmjet models, we demonstrate that the effect of asymmetry on final state rapidity distribution can be quantitatively related to the average rapidity shift via a third-order polynomial with a dominantly linear term. The coefficients of the polynomial are proportional to the rapidity shift with the dependence being sensitive to the details of the rapidity distribution. Experimental estimates of the spectator asymmetry through the measurement of spectator nucleons in a zero-degree calorimeter may hence be used to further constrain the initial conditions in ultra-relativistic heavy-ion collisions.

Cancer and Complementary Health Approaches

MedlinePlus

... Cancer Institute's activities in research on complementary health approaches. Toll-free in the U.S.: 1-800-4-CANCER (1-800-422-6237) Web ... complementary health approaches. Information on complementary health approaches in cancer treatment: ...

Gait asymmetry: composite scores for mechanical analyses of sprint running.

PubMed

Exell, T A; Gittoes, M J R; Irwin, G; Kerwin, D G

2012-04-05

Gait asymmetry analyses are beneficial from clinical, coaching and technology perspectives. Quantifying overall athlete asymmetry would be useful in allowing comparisons between participants, or between asymmetry and other factors, such as sprint running performance. The aim of this study was to develop composite kinematic and kinetic asymmetry scores to quantify athlete asymmetry during maximal speed sprint running. Eight male sprint trained athletes (age 22±5 years, mass 74.0±8.7 kg and stature 1.79±0.07 m) participated in this study. Synchronised sagittal plane kinematic and kinetic data were collected via a CODA motion analysis system, synchronised to two Kistler force plates. Bilateral, lower limb data were collected during the maximal velocity phase of sprint running (velocity=9.05±0.37 ms(-1)). Kinematic and kinetic composite asymmetry scores were developed using the previously established symmetry angle for discrete variables associated with successful sprint performance and comparisons of continuous joint power data. Unlike previous studies quantifying gait asymmetry, the scores incorporated intra-limb variability by excluding variables from the composite scores that did not display significantly larger (p<0.05) asymmetry than intra-limb variability. The variables that contributed to the composite scores and the magnitude of asymmetry observed for each measure varied on an individual participant basis. The new composite scores indicated the inter-participant differences that exist in asymmetry during sprint running and may serve to allow comparisons between overall athlete asymmetry with other important factors such as performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Precise discussion of time-reversal asymmetries in B-meson decays

DOE PAGES

Morozumi, Takuya; Okane, Hideaki; Umeeda, Hiroyuki

2015-02-26

BaBar collaboration announced that they observed time reversal (T) asymmetry through B meson system. In the experiment, time dependencies of two distinctive processes, B_ →B¯ 0 and B¯ 0 → B_ (– expresses CP value) are compared with each other. In our study, we examine event number difference of these two processes. In contrast to the BaBar asymmetry, the asymmetry of events number includes the overall normalization difference for rates. Time dependence of the asymmetry is more general and it includes terms absent in one used by BaBar collaboration. Both of the BaBar asymmetry and ours are naively thought tomore » be T-odd since two processes compared are related with flipping time direction. We investigate the time reversal transformation property of our asymmetry. Using our notation, one can see that the asymmetry is not precisely a T-odd quantity, taking into account indirect CP and CPT violation of K meson systems. The effect of ϵK is extracted and gives rise to O(10 –3) contribution. The introduced parameters are invariant under rephasing of quarks so that the coefficients of our asymmetry are expressed as phase convention independent quantities. Some combinations of the asymmetry enable us to extract parameters for wrong sign decays of B d meson, CPT violation, etc. As a result, we also study the reason why the T-even terms are allowed to contribute to the asymmetry, and find that several conditions are needed for the asymmetry to be a T-odd quantity.« less

A voxel-based approach to gray matter asymmetries.

PubMed

Luders, E; Gaser, C; Jancke, L; Schlaug, G

2004-06-01

Voxel-based morphometry (VBM) was used to analyze gray matter (GM) asymmetries in a large sample (n = 60) of male and female professional musicians with and without absolute pitch (AP). We chose to examine these particular groups because previous studies using traditional region-of-interest (ROI) analyses have shown differences in hemispheric asymmetry related to AP and gender. Voxel-based methods may have advantages over traditional ROI-based methods since the analysis can be performed across the whole brain with minimal user bias. After determining that the VBM method was sufficiently sensitive for the detection of differences in GM asymmetries between groups, we found that male AP musicians were more leftward lateralized in the anterior region of the planum temporale (PT) than male non-AP musicians. This confirmed the results of previous studies using ROI-based methods that showed an association between PT asymmetry and the AP phenotype. We further observed that male non-AP musicians revealed an increased leftward GM asymmetry in the postcentral gyrus compared to female non-AP musicians, again corroborating results of a previously published study using ROI-based methods. By analyzing hemispheric GM differences across our entire sample, we were able to partially confirm findings of previous studies using traditional morphometric techniques, as well as more recent, voxel-based analyses. In addition, we found some unusually pronounced GM asymmetries in our musician sample not previously detected in subjects unselected for musical training. Since we were able to validate gender- and AP-related brain asymmetries previously described using traditional ROI-based morphometric techniques, the results of our analyses support the use of VBM for examinations of GM asymmetries.

Asymmetry in power-law magnitude correlations.

PubMed

Podobnik, Boris; Horvatić, Davor; Tenenbaum, Joel N; Stanley, H Eugene

2009-07-01

Time series of increments can be created in a number of different ways from a variety of physical phenomena. For example, in the phenomenon of volatility clustering-well-known in finance-magnitudes of adjacent increments are correlated. Moreover, in some time series, magnitude correlations display asymmetry with respect to an increment's sign: the magnitude of |x_{i}| depends on the sign of the previous increment x_{i-1} . Here we define a model-independent test to measure the statistical significance of any observed asymmetry. We propose a simple stochastic process characterized by a an asymmetry parameter lambda and a method for estimating lambda . We illustrate both the test and process by analyzing physiological data.

Why sex hormones matter for neuroscience: A very short review on sex, sex hormones, and functional brain asymmetries.

PubMed

Hausmann, Markus

2017-01-02

Biological sex and sex hormones are known to affect functional cerebral asymmetries (FCAs). Men are generally more lateralized than women. The effect size of this sex difference is small but robust. Some of the inconsistencies in the literature may be explained by sex-related hormonal differences. Most studies focusing on neuromodulatory properties of sex hormones on FCAs have investigated women during the menstrual cycle. Although contradictions exist, these studies have typically shown that levels of estradiol and/or progesterone correlate with the degree of FCAs, suggesting that sex differences in FCAs partially depend on hormonal state and day of testing. The results indicate that FCAs are not fixed but are hormone dependent, and as such they can dynamically change within relatively short periods throughout life. Many issues raised in this Mini-Review refer not only to FCAs but also to other aspects of functional brain organization, such as functional connectivity within and between the cerebral hemispheres. Our understanding of sex differences in brain and behavior as well as their clinical relevance will improve significantly if more studies routinely take sex and sex hormones into account. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Facial asymmetry quantitative evaluation in oculoauriculovertebral spectrum.

PubMed

Manara, Renzo; Schifano, Giovanni; Brotto, Davide; Mardari, Rodica; Ghiselli, Sara; Gerunda, Antonio; Ghirotto, Cristina; Fusetti, Stefano; Piacentile, Katherine; Scienza, Renato; Ermani, Mario; Martini, Alessandro

2016-03-01

Facial asymmetries in oculoauriculovertebral spectrum (OAVS) patients might require surgical corrections that are mostly based on qualitative approach and surgeon's experience. The present study aimed to develop a quantitative 3D CT imaging-based procedure suitable for maxillo-facial surgery planning in OAVS patients. Thirteen OAVS patients (mean age 3.5 ± 4.0 years; range 0.2-14.2, 6 females) and 13 controls (mean age 7.1 ± 5.3 years; range 0.6-15.7, 5 females) who underwent head CT examination were retrospectively enrolled. Eight bilateral anatomical facial landmarks were defined on 3D CT images (porion, orbitale, most anterior point of frontozygomatic suture, most superior point of temporozygomatic suture, most posterior-lateral point of the maxilla, gonion, condylion, mental foramen) and distance from orthogonal planes (in millimeters) was used to evaluate the asymmetry on each axis and to calculate a global asymmetry index of each anatomical landmark. Mean asymmetry values and relative confidence intervals were obtained from the control group. OAVS patients showed 2.5 ± 1.8 landmarks above the confidence interval while considering the global asymmetry values; 12 patients (92%) showed at least one pathologically asymmetric landmark. Considering each axis, the mean number of pathologically asymmetric landmarks increased to 5.5 ± 2.6 (p = 0.002) and all patients presented at least one significant landmark asymmetry. Modern CT-based 3D reconstructions allow accurate assessment of facial bone asymmetries in patients affected by OAVS. The evaluation as a global score and in different orthogonal axes provides precise quantitative data suitable for maxillo-facial surgical planning. CT-based 3D reconstruction might allow a quantitative approach for planning and following-up maxillo-facial surgery in OAVS patients.

What determines direction of asymmetry: genes, environment or chance?

PubMed Central

2016-01-01

Conspicuous asymmetries seen in many animals and plants offer diverse opportunities to test how the development of a similar morphological feature has evolved in wildly different types of organisms. One key question is: do common rules govern how direction of asymmetry is determined (symmetry is broken) during ontogeny to yield an asymmetrical individual? Examples from numerous organisms illustrate how diverse this process is. These examples also provide some surprising answers to related questions. Is direction of asymmetry in an individual determined by genes, environment or chance? Is direction of asymmetry determined locally (structure by structure) or globally (at the level of the whole body)? Does direction of asymmetry persist when an asymmetrical structure regenerates following autotomy? The answers vary greatly for asymmetries as diverse as gastropod coiling direction, flatfish eye side, crossbill finch bill crossing, asymmetrical claws in shrimp, lobsters and crabs, katydid sound-producing structures, earwig penises and various plant asymmetries. Several examples also reveal how stochastic asymmetry in mollusc and crustacean early cleavage, in Drosophila oogenesis, and in Caenorhabditis elegans epidermal blast cell movement, is a normal component of deterministic development. Collectively, these examples shed light on the role of genes as leaders or followers in evolution. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’. PMID:27821528

Longitudinal Study of the Emerging Functional Connectivity Asymmetry of Primary Language Regions during Infancy.

PubMed

Emerson, Robert W; Gao, Wei; Lin, Weili

2016-10-19

Asymmetry in the form of left-hemisphere lateralization is a striking characteristic of the cerebral regions involved in the adult language network. In this study, we leverage a large sample of typically developing human infants with longitudinal resting-state functional magnetic resonance imaging scans to delineate the trajectory of interhemispheric functional asymmetry in language-related regions during the first 2 years of life. We derived the trajectory of interhemispheric functional symmetry of the inferior frontal gyrus (IFG) and superior temporal gyrus (STG), the sensory and visual cortices, and two higher-order regions within the intraparietal sulcus and dorsolateral prefrontal cortex. Longitudinal models revealed a best fit with quadratic age terms and showed significant estimated coefficients of determination for both the IFG (r 2 = 0.261, p < 0.001) and the STG (r 2 = 0.142, p < 0.001) regions while all other regions were best modeled by log-linear increases. These inverse-U-shaped functions of the language regions peaked at ∼11.5 months of age, indicating that a transition toward asymmetry began in the second year. This shift was accompanied by an increase in the functional connectivity of these regions within the left hemisphere. Finally, we detected an association between the trajectory of the IFG and language outcomes at 4 years of age (χ 2 = 10.986, p = 0.011). Our results capture the developmental timeline of the transition toward interhemispheric functional asymmetry during the first 2 years of life. More generally, our findings suggest that increasing interhemispheric functional symmetry in the first year might be a general principle of the developing brain, governing different functional systems, including those that will eventually become lateralized in adulthood. Cross-sectional studies of the language system in early infancy suggest that the basic neural mechanisms are in place even before birth. This study represents the first of its kind

A Large Asymmetry in the Distribution of Faint Stars in the Inner Galaxy

NASA Astrophysics Data System (ADS)

Parker, J. E.; Humphreys, R. M.; Larsen, J. A.

2002-12-01

We present a star count analysis of the faint stars on either side of the Sun-Center line, from l=±20 deg -- ±75 deg and b=+20 deg -- +50 deg with data from 40 POSS I fields. Larsen & Humphreys (1996) found a significant asymmetry in the number of faint blue stars on either side of the line to the Galactic center with significantly more stars observed in the first quadrant. Using a galactic model, we chose color ranges to distinguish between halo/thick disk and old disk stellar populations. Our results indicate that the stellar excess is comprised of mainly halo/thick disk stars and that it increases with fainter magnitudes. In addition, we analyzed the star counts for 40 fields above the plane compared to their 40 complementary fields below the plane (b=±20 deg -- ±50 deg). We find that the excess is also present in quadrant I below the plane. It is possible that the excess in star counts may be due to a bar--induced ``wake", an interaction of the disk by a merger, or a result of a triaxial thick disk/inner halo. Spectroscopic observations have been made using both the CTIO 4 meter and the KPNO WIYN 3.5 meter telescopes with HYDRA to measure the radial velocities and classify nearly 1000 stars. The objective is to determine the extent of the asymmetry and the nature and kinematics of the stars responsible.

A brain stress test: Cerebral perfusion during memory encoding in mild cognitive impairment.

PubMed

Xie, Long; Dolui, Sudipto; Das, Sandhitsu R; Stockbower, Grace E; Daffner, Molly; Rao, Hengyi; Yushkevich, Paul A; Detre, John A; Wolk, David A

2016-01-01

Arterial spin labeled perfusion magnetic resonance imaging (ASL MRI) provides non-invasive quantification of cerebral blood flow, which can be used as a biomarker of brain function due to the tight coupling between cerebral blood flow (CBF) and brain metabolism. A growing body of literature suggests that regional CBF is altered in neurodegenerative diseases. Here we examined ASL MRI CBF in subjects with amnestic mild cognitive impairment (n = 65) and cognitively normal healthy controls (n = 62), both at rest and during performance of a memory-encoding task. As compared to rest, task-enhanced ASL MRI improved group discrimination, which supports the notion that physiologic measures during a cognitive challenge, or "stress test", may increase the ability to detect subtle functional changes in early disease stages. Further, logistic regression analysis demonstrated that ASL MRI and concomitantly acquired structural MRI provide complementary information of disease status. The current findings support the potential utility of task-enhanced ASL MRI as a biomarker in early Alzheimer's disease.

Discriminating different Z{sup '}'s via asymmetries at the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou Zhongqiu; Xiao Bo; Wang Youkai

2011-05-01

In practice the asymmetry, which is defined based on the angular distribution of the final states in scattering or decay processes, can be utilized to scrutinize underlying dynamics in and/or beyond the standard model (BSM). As one of the possible BSM physics which might be discovered early at the LHC, extra neutral gauge bosons Z{sup '}'s are theoretically well motivated. Once Z{sup '}'s are discovered at the LHC, it is crucial to discriminate different Z{sup '}'s in various BSM. In principle such a task can be accomplished by measuring the angular distribution of the final states which are produced viamore » Z{sup '}-mediated processes. In the real data analysis, asymmetry is always adopted. In the literature several asymmetries have been proposed at the LHC. Based on these works, we stepped further on to study how to optimize the asymmetries in the left-right model and the sequential standard model, as the examples of BSM. In this paper, we examined four kinds of asymmetries, namely, rapidity-dependent forward-backward asymmetry, oneside forward-backward asymmetry, central charge asymmetry, and edge charge asymmetry (see text for details), with l{sup +}l{sup -} (l=e, {mu}), bb, and tt as the final states. In the calculations with bb and tt final states, the QCD-induced higher-order contributions to the asymmetric cross section were also included. For each kind of final state, we estimated the four kinds of asymmetries and especially the optimal cut usually associated with the definition of the asymmetry. Our numerical results indicated that the capacity to discriminate Z{sup '} models can be improved by imposing the optimal cuts.« less

Forward-backward asymmetry in top quark-antiquark production

DOE PAGES

Abazov, Victor Mukhamedovich

2011-12-12

We present a measurement of forward-backward asymmetry in top quark-antiquark production in proton-antiproton collisions in the final state containing a lepton and at least four jets. Using a dataset corresponding to an integrated luminosity of 5.4 fb -1, collected by the D0 experiment at the Fermilab Tevatron Collider, we measure the t{bar t} forward-backward asymmetry to be (9.2 ± 3.7)% at the reconstruction level. When corrected for detector acceptance and resolution, the asymmetry is found to be (19.6 ± 6.5)%. We also measure a corrected asymmetry based on the lepton from a top quark decay, found to be (15.2 ±more » 4.0)%. The results are compared to predictions based on the next-to-leading-order QCD generator mc@nlo. The sensitivity of the measured and predicted asymmetries to the modeling of gluon radiation is discussed.« less

Infant Positioning, Baby Gear Use, and Cranial Asymmetry.

PubMed

Zachry, Anne H; Nolan, Vikki G; Hand, Sarah B; Klemm, Susan A

2017-12-01

Objectives This study aimed to identify predictors of cranial asymmetry. We hypothesize that among infants diagnosed with cranial asymmetry in the sampled region, there is an association between exposure to more time in baby gear and less awake time in prone and side-lying than in infants who do not present with this condition. Methods The study employed a cross sectional survey of caregivers of typically developing infants and infants diagnosed with cranial asymmetry. Results A mutivariable model reveals that caregivers of children who are diagnosed with cranial asymmetry report their children spending significantly less time in prone play than those children without a diagnosis of cranial asymmetry. Side-lying and time spent in baby gear did not attain statistical significance. Conclusions for Practice Occupational therapists, physical therapists, pediatricians, nurses and other health care professionals must provide parents with early education about the importance of varying positions and prone play in infancy and address fears and concerns that may serve as barriers to providing prone playtime.

Bottom-quark forward-backward asymmetry in the standard model and beyond.

PubMed

Grinstein, Benjamín; Murphy, Christopher W

2013-08-09

We computed the bottom-quark forward-backward asymmetry at the Tevatron in the standard model (SM) and for several new physics scenarios. Near the Z pole, the SM bottom asymmetry is dominated by tree level exchanges of electroweak gauge bosons. While above the Z pole, next-to-leading order QCD dominates the SM asymmetry as was the case with the top-quark forward-backward asymmetry. Light new physics, M(NP)≲150  GeV, can cause significant deviations from the SM prediction for the bottom asymmetry. The bottom asymmetry can be used to distinguish between competing new physics (NP) explanations of the top asymmetry based on how the NP interferes with s-channel gluon and Z exchange.

Birth order and fluctuating asymmetry: a first look.

PubMed Central

Lalumière, M L; Harris, G T; Rice, M E

1999-01-01

We investigated the hypothesis that maternal immunoreactivity to male-specific features of the foetus can increase developmental instability. We predicted that the participants' number of older brothers would be positively related to the fluctuating asymmetry of ten bilateral morphological traits. The participants were 40 adult male psychiatric patients and 31 adult male hospital employees. Consistent with the hypothesis, the participants' number of older brothers--but not number of older sisters, younger brothers or younger sisters--was positively associated with fluctuating asymmetry. The patients had significantly larger fluctuating asymmetry scores and tended to have more older brothers than the employees, but the positive relationship between the number of older brothers and fluctuating asymmetry was observed in both groups. PMID:10643079

The association between static pelvic asymmetry and low back pain.

PubMed

Levangie, P K

1999-06-15

A cross-sectional case-control approach was used to estimate the association between low back pain of less than 12 months' duration and pelvic asymmetry among 21-50-year-old patients seeking physical therapy services. To evaluate the premise that asymmetrical positioning of the innominates of the pelvis is a source of low back pain. No published studies have been conducted to evaluate systematically the association between low back pain and pelvic asymmetry in a clinic-based sample. Pelvic landmark data were obtained in 144 cases and 138 control subjects. The associations of low back pain with levels of pelvic asymmetry were estimated by use of odds ratios and 95% confidence intervals. Effect modification and confounding of the low back pain-pelvic asymmetry association by several factors was assessed and alternative asymmetry measures considered. Pelvic asymmetry was not positively associated with low back pain in any way that seemed clinically meaningful. Asymmetry of posterior superior iliac spine landmarks showed some evidence of a weak positive association with low back pain. In the absence of meaningful positive association between pelvic asymmetry and low back pain, evaluation and treatment strategies based on this premise should be questioned.

Symmetry and asymmetry in the human brain

NASA Astrophysics Data System (ADS)

Hugdahl, Kenneth

2005-10-01

Structural and functional asymmetry in the human brain and nervous system is reviewed in a historical perspective, focusing on the pioneering work of Broca, Wernicke, Sperry, and Geschwind. Structural and functional asymmetry is exemplified from work done in our laboratory on auditory laterality using an empirical procedure called dichotic listening. This also involves different ways of validating the dichotic listening procedure against both invasive and non-invasive techniques, including PET and fMRI blood flow recordings. A major argument is that the human brain shows a substantial interaction between structurally, or "bottom-up" asymmetry and cognitively, or "top-down" modulation, through a focus of attention to the right or left side in auditory space. These results open up a more dynamic and interactive view of functional brain asymmetry than the traditional static view that the brain is lateralized, or asymmetric, only for specific stimuli and stimulus properties.

Cerebral Palsy (For Parents)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Parents / Cerebral Palsy What's in this ... Ahead Print en español Parálisis cerebral What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder that affects ...

The Relationship Between Asymmetry and Athletic Performance: A Critical Review.

PubMed

Maloney, Sean J

2018-05-08

Maloney, SJ. The relationship between asymmetry and athletic performance: A critical review. J Strength Cond Res XX(X): 000-000, 2018-Symmetry may be defined as the quality to demonstrate an exact correspondence of size, shape, and form when split along a given axis. Although it has been widely asserted that the bilateral asymmetries are detrimental to athletic performance, research does not wholly support such an association. Moreover, the research rarely seeks to distinguish between different types of bilateral asymmetry. Fluctuating asymmetries describe bilateral differences in anthropometric attributes, such as nostril width and ear size, and are thought to represent the developmental stability of an organism. There is evidence to suggest that fluctuating asymmetries may be related to impaired athletic performance, although contradictory findings have been reported. Sporting asymmetries is a term that may better describe bilateral differences in parameters, such as force output or jump height. These asymmetries are likely to be a function of limb dominance and magnified by long-standing participation within sport. Sporting asymmetries do not seem to carry a clear influence on athletic performance measures. Given the vast discrepancy in the methodologies used by different investigations, further research is warranted. Recent investigations have demonstrated that training interventions can reduce sporting asymmetries and improve performance. However, studies have not sought to determine whether the influence of sporting asymmetry is independent of improvements in neuromuscular parameters. It may be hypothesized that the deficient (weaker) limb has a greater potential for adaptation in comparison to the strong limb and may demonstrate greater responsiveness to training.

Geometric asymmetry driven Janus micromotors.

PubMed

Zhao, Guanjia; Pumera, Martin

2014-10-07

The production and application of nano-/micromotors is of great importance. In order for the motors to work, asymmetry in their chemical composition or physical geometry must be present if no external asymmetric field is applied. In this paper, we present a "coconut" micromotor made of platinum through the partial or complete etching of the silica templates. It was shown that although both the inner and outer surfaces are made of the same material (Pt), motion of the structure can be observed as the convex surface is capable of generating oxygen bubbles. This finding shows that not only the chemical asymmetry of the micromotor, but also its geometric asymmetry can lead to fast propulsion of the motor. Moreover, a considerably higher velocity can be seen for partially etched coconut structures than the velocities of Janus or fully etched, shell-like motors. These findings will have great importance on the design of future micromotors.

Asymmetry dependence of the caloric curve for mononuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoel, C.; Sobotka, L. G.; Charity, R. J.

2007-01-15

The asymmetry dependence of the caloric curve, for mononuclear configurations, is studied as a function of neutron-to-proton asymmetry with a model that allows for independent variation of the neutron and proton surface diffusenesses. The evolution of the effective mass with density and excitation is included in a schematic fashion and the entropies are extracted in a local density approximation. The plateau in the caloric curve displays only a slight sensitivity to the asymmetry.

Complementary and Integrative Medicine

MedlinePlus

... medical treatments that are not part of mainstream medicine. When you are using these types of care, it may be called complementary, integrative, or alternative medicine. Complementary medicine is used together with mainstream medical ...

CP asymmetry in charged Higgs decays to chargino-neutralino pairs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, Mariana; Turan, Ismail

2007-10-01

We analyze the charge-parity (CP) asymmetry in the charged Higgs boson decays to chargino-neutralino pairs, H{sup {+-}}{yields}{chi}{sub i}{sup {+-}}{chi}{sub j}{sup 0}, i=1, 2, j=1,...,4. We show first that these modes have a large branching ratio for m{sub H{sup {+-}}} > or approx. 600 GeV. We use Cutkosky rules to obtain the analytical formulas needed for the evaluation of the asymmetry under consideration. We then calculate the CP asymmetry in chargino-neutralino decays by including supersymmetric mass bounds, as well as constraints from b{yields}s{gamma} (g-2){sub {mu}}, {delta}{rho} and electric dipole moments. Finally, we discuss observability of the asymmetry at the LHC bymore » calculating the number of required charged Higgs events to observe the asymmetry for each decay channel. We show that the inclusion of constraints considerably reduces the projected CP asymmetry, and that the optimal channel for observing the asymmetry is H{sup {+-}}{yields}{chi}{sub 1}{sup {+-}}{chi}{sub 2}{sup 0}.« less

Subcycle dynamics of Coulomb asymmetry in strong elliptical laser fields.

PubMed

Li, Min; Liu, Yunquan; Liu, Hong; Ning, Qicheng; Fu, Libin; Liu, Jie; Deng, Yongkai; Wu, Chengyin; Peng, Liang-You; Peng, Liangyou; Gong, Qihuang

2013-07-12

We measure photoelectron angular distributions of noble gases in intense elliptically polarized laser fields, which indicate strong structure-dependent Coulomb asymmetry. Using a dedicated semiclassical model, we have disentangled the contribution of direct ionization and multiple forward scattering on Coulomb asymmetry in elliptical laser fields. Our theory quantifies the roles of the ionic potential and initial transverse momentum on Coulomb asymmetry, proving that the small lobes of asymmetry are induced by direct ionization and the strong asymmetry is induced by multiple forward scattering in the ionic potential. Both processes are distorted by the Coulomb force acting on the electrons after tunneling. Lowering the ionization potential, the relative contribution of direct ionization on Coulomb asymmetry substantially decreases and Coulomb focusing on multiple rescattering is more important. We do not observe evident initial longitudinal momentum spread at the tunnel exit according to our simulation.

Special Section: Complementary and Alternative Medicine (CAM):Quiz on Complementary and Alternative Medicine

MedlinePlus

... Special Section CAM Quiz on Complementary and Alternative Medicine Past Issues / Winter 2009 Table of Contents For ... low back pain. True False Complementary and alternative medicine (CAM) includes: Meditation Chiropractic Use of natural products, ...

CMB hemispherical asymmetry from non-linear isocurvature perturbations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assadullahi, Hooshyar; Wands, David; Firouzjahi, Hassan

2015-04-01

We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear δ N formalism to calculate the non-Gaussianity of the primordial density and isocurvature perturbations due to the presence of non-adiabatic, but approximately scale-invariant field fluctuations during multi-field inflation. This local-type non-Gaussianity leads to a correlation between very long wavelength inhomogeneities, larger than our observable horizon, and smaller scale fluctuations in the radiation and matter density. Matter isocurvature perturbations contribute primarily to low CMB multipoles and hence can lead to a hemisphericalmore » asymmetry on large angular scales, with negligible asymmetry on smaller scales. In curvaton models, where the matter isocurvature perturbation is partly correlated with the primordial density perturbation, we are unable to obtain a significant asymmetry on large angular scales while respecting current observational constraints on the observed quadrupole. However in the axion model, where the matter isocurvature and primordial density perturbations are uncorrelated, we find it may be possible to obtain a significant asymmetry due to isocurvature modes on large angular scales. Such an isocurvature origin for the hemispherical asymmetry would naturally give rise to a distinctive asymmetry in the CMB polarisation on large scales.« less

Femoral head asymmetry and coxa magna: anatomic study.

PubMed

Young, Ernest Y; Gebhart, Jeremy J; Bajwa, Navkirat; Cooperman, Daniel R; Ahn, Nicholas U

2014-06-01

Coxa magna, the asymmetrical circumferential enlargement of the femoral head, is an important sequela of pediatric disorders such as Legg-Calvé-Perthes disease. Definitions vary because of lack of controls and a scarcity of research on the distribution of the femoral head asymmetry. This study aims at defining the normal distribution of asymmetry between the left and the right femoral head and neck in the population and how demographics affect these properties. The study also looked at the distribution of side dominance (left or right). This study measured 230 paired femurs from individuals (20 to 40 y old) distributed for sex and ethnicity. The height and weight of the individuals were also recorded. The femoral head diameter and minimal femoral neck diameter in the anteroposterior view were measured on each paired femurs. The absolute and percent differences were determined to define asymmetry. Most of the population fell within 3% of asymmetry for the femoral head and 4% for the femoral neck. The maximum head percent asymmetry was 7.4%. Absolute difference in millimeters to percent asymmetry showed a ratio of 2:1 for the femoral head and 3:1 for the femoral neck. African Americans showed greater femoral head symmetry and a bias toward left-sided femoral head and neck enlargement when compared with their white counterparts. There was a high degree of symmetry between the left and right femoral heads and necks, which supports definitions found in the literature that define coxa magna above 10%. This study defines asymmetry in the femoral head in the normal population, which will help to define a quantitative definition of coxa magna.

Micropatterned mammalian cells exhibit phenotype-specific left-right asymmetry.

PubMed

Wan, Leo Q; Ronaldson, Kacey; Park, Miri; Taylor, Grace; Zhang, Yue; Gimble, Jeffrey M; Vunjak-Novakovic, Gordana

2011-07-26

Left-right (LR) asymmetry (handedness, chirality) is a well-conserved biological property of critical importance to normal development. Changes in orientation of the LR axis due to genetic or environmental factors can lead to malformations and disease. While the LR asymmetry of organs and whole organisms has been extensively studied, little is known about the LR asymmetry at cellular and multicellular levels. Here we show that the cultivation of cell populations on micropatterns with defined boundaries reveals intrinsic cell chirality that can be readily determined by image analysis of cell alignment and directional motion. By patterning 11 different types of cells on ring-shaped micropatterns of various sizes, we found that each cell type exhibited definite LR asymmetry (p value down to 10(-185)) that was different between normal and cancer cells of the same type, and not dependent on surface chemistry, protein coating, or the orientation of the gravitational field. Interestingly, drugs interfering with actin but not microtubule function reversed the LR asymmetry in some cell types. Our results show that micropatterned cell populations exhibit phenotype-specific LR asymmetry that is dependent on the functionality of the actin cytoskeleton. We propose that micropatterning could potentially be used as an effective in vitro tool to study the initiation of LR asymmetry in cell populations, to diagnose disease, and to study factors involved with birth defects in laterality.

Mapping the stability of human brain asymmetry across five sex-chromosome aneuploidies.

PubMed

Lin, Amy; Clasen, Liv; Lee, Nancy Raitano; Wallace, Gregory L; Lalonde, Francois; Blumenthal, Jonathan; Giedd, Jay N; Raznahan, Armin

2015-01-07

The human brain displays stereotyped and early emerging patterns of cortical asymmetry in health. It is unclear if these asymmetries are highly sensitive to genetic and environmental variation or fundamental features of the brain that can survive severe developmental perturbations. To address this question, we mapped cortical thickness (CT) asymmetry in a group of genetically defined disorders known to impact CT development. Participants included 137 youth with one of five sex-chromosome aneuploidies [SCAs; XXX (n = 28), XXY (n = 58), XYY (n = 26), XXYY (n = 20), and XXXXY (n = 5)], and 169 age-matched typically developing controls (80 female). In controls, we replicated previously reported rightward inferior frontal and leftward lateral parietal CT asymmetry. These opposing frontoparietal CT asymmetries were broadly preserved in all five SCA groups. However, we also detected foci of shifting CT asymmetry with aneuploidy, which fell almost exclusively within regions of significant CT asymmetry in controls. Specifically, X-chromosome aneuploidy accentuated normative rightward inferior frontal asymmetries, while Y-chromosome aneuploidy reversed normative rightward medial prefrontal and lateral temporal asymmetries. These findings indicate that (1) the stereotyped normative pattern of opposing frontoparietal CT asymmetry arises from developmental mechanisms that can withstand gross chromosomal aneuploidy and (2) X and Y chromosomes can exert focal, nonoverlapping and directionally opposed influences on CT asymmetry within cortical regions of significant asymmetry in health. Our study attests to the resilience of developmental mechanisms that support the global patterning of CT asymmetry in humans, and motivates future research into the molecular bases and functional consequences of sex chromosome dosage effects on CT asymmetry. Copyright © 2015 the authors 0270-6474/15/350140-06$15.00/0.

Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.

PubMed

Ma, Xiaomei; Wang, Di; Zhou, Yujing; Zhuo, Chuanjun; Qin, Wen; Zhu, Jiajia; Yu, Chunshui

2016-04-01

blood flow-amplitude of low-frequency fluctuations couplings compared with those of healthy females. The alterations in the relative cerebral blood flow and amplitude of low-frequency fluctuations in schizophrenia are sex-specific, which should be considered in future neuroimaging studies. The relative cerebral blood flow and amplitude of low-frequency fluctuations have different sensitivity in detecting changes in neuronal activity in schizophrenia and can provide complementary information. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Common Genetic Variant in VIT Is Associated with Human Brain Asymmetry.

PubMed

Tadayon, Sayed H; Vaziri-Pashkam, Maryam; Kahali, Pegah; Ansari Dezfouli, Mitra; Abbassian, Abdolhossein

2016-01-01

Brain asymmetry varies across individuals. However, genetic factors contributing to this normal variation are largely unknown. Here we studied variation of cortical surface area asymmetry in a large sample of subjects. We performed principal component analysis (PCA) to capture correlated asymmetry variation across cortical regions. We found that caudal and rostral anterior cingulate together account for a substantial part of asymmetry variation among individuals. To find SNPs associated with this subset of brain asymmetry variation we performed a genome-wide association study followed by replication in an independent cohort. We identified one SNP (rs11691187) that had genome-wide significant association (P Combined = 2.40e-08). The rs11691187 is in the first intron of VIT. In a follow-up analysis, we found that VIT gene expression is associated with brain asymmetry in six donors of the Allen Human Brain Atlas. Based on these findings we suggest that VIT contributes to normal brain asymmetry variation. Our results can shed light on disorders associated with altered brain asymmetry.

Frontal EEG asymmetry as a moderator and mediator of emotion.

PubMed

Coan, James A; Allen, John J B

2004-10-01

Frontal EEG asymmetry appears to serve as (1) an individual difference variable related to emotional responding and emotional disorders, and (2) a state-dependent concomitant of emotional responding. Such findings, highlighted in this review, suggest that frontal EEG asymmetry may serve as both a moderator and a mediator of emotion- and motivation-related constructs. Unequivocal evidence supporting frontal EEG asymmetry as a moderator and/or mediator of emotion is lacking, as insufficient attention has been given to analyzing the frontal EEG asymmetries in terms of moderators and mediators. The present report reviews the frontal EEG asymmetry literature from the framework of moderators and mediators, and overviews data analytic strategies that would support claims of moderation and mediation.

A theoretical explanation for the Central Molecular Zone asymmetry

NASA Astrophysics Data System (ADS)

Sormani, Mattia C.; Treß, Robin G.; Ridley, Matthew; Glover, Simon C. O.; Klessen, Ralf S.; Binney, James; Magorrian, John; Smith, Rowan

2018-04-01

It has been known for more than 30 yr that the distribution of molecular gas in the innermost 300 parsecs of the Milky Way, the Central Molecular Zone, is strongly asymmetric. Indeed, approximately three quarters of molecular emission come from positive longitudes, and only one quarter from negative longitudes. However, despite much theoretical effort, the origin of this asymmetry has remained a mystery. Here, we show that the asymmetry can be neatly explained by unsteady flow of gas in a barred potential. We use high-resolution 3D hydrodynamical simulations coupled to a state-of-the-art chemical network. Despite the initial conditions and the bar potential being point symmetric with respect to the Galactic Centre, asymmetries develop spontaneously due to the combination of a hydrodynamical instability known as the `wiggle instability' and the thermal instability. The observed asymmetry must be transient: observations made tens of megayears in the past or in the future would often show an asymmetry in the opposite sense. Fluctuations of amplitude comparable to the observed asymmetry occur for a large fraction of time in our simulations, and suggest that the present is not an exceptional moment in the life of our Galaxy.

Asymmetry of intronic pre-miRNA structures in functional RISC assembly

PubMed Central

Lin, Shi-Lung; Chang, Donald; Ying, Shao-Yao

2006-01-01

The two oligonucleotide strands of a siRNA duplex are functionally asymmetric in assembling the RNAi effector, RNA-induced gene silencing complex (RISC). Based on this asymmetric RISC assembly model in vitro, formation of a microRNA (miRNA) and complementary miRNA (miRNA*) duplex was proposed to be an essential step for the assembly of miRNA-associated RISC (miRISC). We observed here that a strong structural bias exists in the selection of a mature miRNA strand for RISC assembly in zebrafish using an intronic miRNA-like vector to target EGFP mRNA for regulation. The position of the stemloop in a precursor miRNA (pre-miRNA) was involved in the determination of miRNA–miRNA* asymmetry of the pre-miRNA stemarm, leading to different miRNA maturation during miRISC assembly. These findings suggest that the miRISC assembly is likely different from the RISC assembly model of siRNA in zebrafish, providing the first in vivo evidence for asymmetric miRISC assembly. PMID:16005165

Temporal Lobe White Matter Asymmetry and Language Laterality in Epilepsy Patients

PubMed Central

Ellmore, Timothy M.; Beauchamp, Michael S.; Breier, Joshua I.; Slater, Jeremy D.; Kalamangalam, Giridhar P.; O’Neill, Thomas J.; Disano, Michael A.; Tandon, Nitin

2009-01-01

Recent studies using diffusion tensor imaging (DTI) have advanced our knowledge of the organization of white matter subserving language function. It remains unclear, however, how DTI may be used to predict accurately a key feature of language organization: its asymmetric representation in one cerebral hemisphere. In this study of epilepsy patients with unambiguous lateralization on Wada testing (19 left and 4 right lateralized subjects; no bilateral subjects), the predictive value of DTI for classifying the dominant hemisphere for language was assessed relative to the existing standard - the intra-carotid Amytal (Wada) procedure. Our specific hypothesis is that language laterality in both unilateral left- and right-hemisphere language dominant subjects may be predicted by hemispheric asymmetry in the relative density of three white matter pathways terminating in the temporal lobe implicated in different aspects of language function: the arcuate (AF), uncinate (UF), and inferior longitudinal fasciculi (ILF). Laterality indices computed from asymmetry of high anisotropy AF pathways, but not the other pathways, classified the majority (19 of 23) of patients using the Wada results as the standard. A logistic regression model incorporating information from DTI of the AF, fMRI activity in Broca’s area, and handedness was able to classify 22 of 23 (95.6%) patients correctly according to their Wada score. We conclude that evaluation of highly anisotropic components of the AF alone has significant predictive power for determining language laterality, and that this markedly asymmetric distribution in the dominant hemisphere may reflect enhanced connectivity between frontal and temporal sites to support fluent language processes. Given the small sample reported in this preliminary study, future research should assess this method on a larger group of patients, including subjects with bihemispheric dominance. PMID:19874899

Soft tissue nasal asymmetry as an indicator of orofacial cleft predisposition.

PubMed

Zhang, Charles; Miller, Steven F; Roosenboom, Jasmien; Wehby, George L; Moreno Uribe, Lina M; Hecht, Jacqueline T; Deleyiannis, Frederic W B; Christensen, Kaare; Marazita, Mary L; Weinberg, Seth M

2018-06-01

The biological relatives of offspring with nonsyndromic orofacial clefts have been shown to exhibit distinctive facial features, including excess asymmetry, which are hypothesized to indicate the presence of genetic risk factors. The significance of excess soft tissue nasal asymmetry in at-risk relatives is unclear and was examined in the present study. Our sample included 164 unaffected parents from families with a history of orofacial clefting and 243 adult controls. Geometric morphometric methods were used to analyze the coordinates of 15 nasal landmarks collected from three-dimensional facial surface images. Following generalized Procrustes analysis, Procrustes ANOVA and MANOVA tests were applied to determine the type and magnitude of nasal asymmetry present in each group. Group differences in mean nasal asymmetry were also assessed via permutation testing. We found that nasal asymmetry in both parents and controls was directional in nature, although the magnitude of the asymmetry was greater in parents. This was confirmed with permutation testing, where the mean nasal asymmetry was significantly different (p < .0001) between parents and controls. The asymmetry was greatest for midline structures and the nostrils. When subsets of parents were subsequently analyzed and compared (parents with bilateral vs. unilateral offspring; parents with left vs. right unilateral offspring), each group showed a similar pattern of asymmetry and could not be distinguished statistically. Thus, the side of the unilateral cleft (right vs. left) in offspring was not associated with the direction of the nasal asymmetry in parents. © 2018 Wiley Periodicals, Inc.

Assessment of postural asymmetry in mild to moderate Parkinson's disease.

PubMed

Geurts, A C H; Boonstra, T A; Voermans, N C; Diender, M G; Weerdesteyn, V; Bloem, B R

2011-01-01

Asymmetry of symptoms of Parkinson's disease is clinically most evident for appendicular impairments. For axial impairments such as freezing of gait, asymmetry is less obvious. To date, asymmetries in balance control in PD patients have seldom been studied. Therefore, in this study we investigated whether postural control can be asymmetrically affected in mild to moderate PD patients. Seventeen PD patients were instructed to stand as still and symmetrically as possible on a dual force-plate during two trials. Dynamic postural asymmetry was assessed by comparing the centre-of-pressure velocities between both legs. Results showed that four patients (24%) had dynamic postural asymmetry, even after correcting for weight-bearing asymmetry. Hence, this study suggests that postural control can be asymmetrical in early PD. However, future studies should investigate the prevalence of dynamic postural asymmetry, in a larger group of PD patients. It should also be further investigated whether this approach can be used as a tool to support the initial diagnosis or monitor disease progression, or as an outcome measure for interventions aimed at improving balance in PD. Copyright © 2010 Elsevier B.V. All rights reserved.

Cerebral Palsy (For Teens)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Teens / Cerebral Palsy What's in this ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

fMRI-vs-MEG evaluation of post-stroke interhemispheric asymmetries in primary sensorimotor hand areas.

PubMed

Altamura, Claudia; Torquati, Kahtya; Zappasodi, Filippo; Ferretti, Antonio; Pizzella, Vittorio; Tibuzzi, Francesco; Vernieri, Fabrizio; Pasqualetti, Patrizio; Landi, Doriana; Del Gratta, Cosimo; Romani, Gian-Luca; Maria Rossini, Paolo; Tecchio, Franca

2007-04-01

Growing evidence emphasizes a positive role of brain ipsilesional (IL) reorganization in stroke patients with partial recovery. Ten patients affected by a monohemispheric stroke in the middle cerebral artery territory underwent functional magnetic resonance (fMRI) and magnetoencephalography (MEG) evaluation of the primary sensory (S1) activation via the same paradigm (median nerve galvanic stimulation). Four patients did not present S1 fMRI activation [Rossini, P.M., Altamura, C., Ferretti, A., Vernieri, F., Zappasodi, F., Caulo, M., Pizzella, V., Del Gratta, C., Romani, G.L., Tecchio, F., 2004. Does cerebrovascular disease affect the coupling between neuronal activity and local haemodynamics? Brain 127, 99-110], although inclusion criteria required bilateral identifiable MEG responses. Mean Euclidean distance between fMRI and MEG S1 activation Talairach coordinates was 10.1+/-2.9 mm, with a 3D intra-class correlation (ICC) coefficient of 0.986. Interhemispheric asymmetries, evaluated by an MEG procedure independent of Talairach transformation, were outside or at the boundaries of reference ranges in 6 patients. In 3 of them, the IL activation presented medial or lateral shift with respect to the omega-shaped post-rolandic area while in the other 3, IL areas were outside the peri-rolandic region. In conclusion, despite dissociated intensity, the MEG and fMRI activations displayed good spatial consistency in stroke patients, thus confirming excessive interhemispheric asymmetries as a suitable indicator of unusual recruitments in the ipsilesional hemisphere, within or outside the peri-rolandic region.

Complementary and Alternative Medicine for Patients

MedlinePlus

... Ask about Your Treatment Research Complementary and Alternative Medicine for Patients Complementary and alternative medicine (CAM) is ... based on scientific evidence from research studies. Complementary medicine refers to treatments that are used with standard ...

Between-subject variability in asymmetry analysis of macular thickness.

PubMed

Alluwimi, Muhammed S; Swanson, William H; Malinovsky, Victor E

2014-05-01

To investigate the use of asymmetry analysis to reduce between-subject variability of macular thickness measurements using spectral domain optical coherence tomography. Sixty-three volunteers (33 young subjects [aged 21 to 35 years] and 30 older subjects [aged 45 to 85 years]) free of eye disease were recruited. Macular images were gathered with the Spectralis optical coherence tomography. An overlay 24- by 24-degree grid was divided into five zones per hemifield, and asymmetry analysis was computed as the difference between superior and inferior zone thicknesses. We hypothesized that the lowest variation and the highest density of ganglion cells will be found approximately 3 to 6 degrees from the foveola, corresponding to zones 1 and 2. For each zone and age group, between-subject SDs were compared for retinal thickness versus asymmetry analysis using an F test. To account for repeated comparisons, p < 0.0125 was required for statistical significance. Axial length and corneal curvature were measured with an IOLMaster. For OD, asymmetry analysis reduced between-subject variability in zones 1 and 2 in both groups (F > 3.2, p < 0.001). Standard deviation for zone 1 dropped from 12.0 to 3.0 μm in the young group and from 11.7 to 2.6 μm in the older group. Standard deviation for zone 2 dropped from 13.6 to 5.3 μm in the young group and from 11.1 to 5.8 μm in the older group. Combining all subjects, neither retinal thickness nor asymmetry analysis showed a strong correlation with axial length or corneal curvature (R² < 0.01). Analysis for OS yielded the same pattern of results, as did asymmetry analyses between eyes (F > 3.8, p < 0.0001). Asymmetry analysis reduced between-subject variability in zones 1 and 2. Combining the five zones together produced a higher between-subject variation of the retinal thickness asymmetry analysis; thus, we encourage clinicians to be cautious when interpreting the asymmetry analysis printouts.

Tension-compression asymmetry of a rolled Mg-Y-Nd alloy

NASA Astrophysics Data System (ADS)

Song, Bo; Pan, Hucheng; Ren, Weijie; Guo, Ning; Wu, Zehong; Xin, Renlong

2017-07-01

In this work, tension and compression deformation behaviors of rolled and aged Mg-Y-Nd alloys were investigated. The microstructure evolution and plastic deformation mechanism during tension and compression were analyzed by combined use of electron backscatter diffraction and a visco-plastic self-consistent crystal plasticity model. The results show that both rolled and aged Mg-Y-Nd sheets show an extremely low yield asymmetry. Elimination of yield asymmetry can be ascribed to the tilted basal texture and suppression of {10-12} twinning. The rolled sheet has almost no yield asymmetry, however exhibits a remarkable strain-hardening behavior asymmetry. Compressed sample shows lower initial strain hardening rate and keeps higher strain hardening rate at the later stage compared with tension. The strain-hardening asymmetry can be aggravated by aging at 280 C. It is considered the limited amount of twins in compression plays the critical role in the strain hardening asymmetry. Finally, the relevant mechanism was analyzed and discussed.

Mercury exposure may influence fluctuating asymmetry in waterbirds.

PubMed

Herring, Garth; Eagles-Smith, Collin A; Ackerman, Joshua T

2017-06-01

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds. Environ Toxicol Chem 2017;36:1599-1605. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Audiometric asymmetry and tinnitus laterality.

PubMed

Tsai, Betty S; Sweetow, Robert W; Cheung, Steven W

2012-05-01

To identify an optimal audiometric asymmetry index for predicting tinnitus laterality. Retrospective medical record review. Data from adult tinnitus patients (80 men and 44 women) were extracted for demographic, audiometric, tinnitus laterality, and related information. The main measures were sensitivity, specificity, positive predictive value (PPV), and receiver operating characteristic (ROC) curves. Three audiometric asymmetry indices were constructed using one, two, or three frequency elements to compute the average interaural threshold difference (aITD). Tinnitus laterality predictive performance of a particular index was assessed by increasing the cutoff or minimum magnitude of the aITD from 10 to 35 dB in 5-dB steps to determine its ROC curve. Single frequency index performance was inferior to the other two (P < .05). Double and triple frequency indices were indistinguishable (P > .05). Two adjoining frequency elements with aITD ≥ 15 dB performed optimally for predicting tinnitus laterality (sensitivity = 0.59, specificity = 0.71, and PPV = 0.76). Absolute and relative magnitudes of hearing loss in the poorer ear were uncorrelated with tinnitus distress. An optimal audiometric asymmetry index to predict tinnitus laterality is one whereby 15 dB is the minimum aITD of two adjoining frequencies, inclusive of the maximal ITD. Tinnitus laterality dependency on magnitude of interaural asymmetry may inform design and interpretation of neuroimaging studies. Monaural acoustic tinnitus therapy may be an initial consideration for asymmetric hearing loss meeting the criterion of aITD ≥ 15 dB. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Sex- and sex hormone-related variations in energy-metabolic frontal brain asymmetries: A magnetic resonance spectroscopy study.

PubMed

Hjelmervik, Helene; Hausmann, Markus; Craven, Alexander R; Hirnstein, Marco; Hugdahl, Kenneth; Specht, Karsten

2018-05-15

Creatine is a key regulator of brain energy homeostasis, and well-balanced creatine metabolism is central in healthy brain functioning. Still, the variability of brain creatine metabolism is largely unattended in magnetic resonance spectroscopy (MRS) research. In the human brain, marginal sex differences in creatine levels have been found in the prefrontal cortex. It is however not known to what degree these sex differences are stable or change with varying gonadal hormone levels. The current study therefore investigated creatine in the prefrontal cortex across the menstrual cycle. In addition, we explored cerebral asymmetries. Creatine, Choline (Cho), N-acetylaspartate (NAA), Myo inositol (mI), and glutamate + glutamine (Glx) were assessed three times in 15 women and 14 men using MRS. Women were tested in cycle phases of varying hormone levels (menstrual, follicular, and luteal phase). Prefrontal creatine was found to change across the menstrual cycle, in a hemisphere-specific manner. Women in the follicular phase showed increased left prefrontal creatine accompanied with reduced right prefrontal creatine, while this asymmetry was not present in the luteal phase. In men, the creatine levels remained stable across three testing sessions. In general, both men and women were found to have higher creatine levels in the left as compared to the right prefrontal cortex. Exploratory analyses of other metabolites showed similar asymmetries in NAA, Cho, and mI, while Cho also showed a menstrual cycle effect. This is the first time that sex hormone-related changes in creatine metabolism have been demonstrated in the human brain. These findings may have important methodological implications for MRS research, as it supports previous concerns against uncritical usage of creatine as a reference measure for other metabolites, assumed to be invariant across individuals and conditions. Copyright © 2018 University of Bergen. Published by Elsevier Inc. All rights reserved.

Hemispheric and facial asymmetry: faces of academe.

PubMed

Smith, W M

1998-11-01

Facial asymmetry (facedness) of selected academic faculty members was studied in relation to brain asymmetry and cognitive specialization. Comparisons of facedness were made among humanities faculty (H), faculty members of mathematics and physics (M-P), psychologists (P), and a group of randomly selected individuals (R). Facedness was defined in terms of the relative sizes (in square centimeters) of the two hemifaces. It was predicted that the four groups would show differences in facedness, namely, H, right face bias; M-P, left face bias; P, no bias; and R, no bias. The predictions were confirmed, and the results interpreted in terms of known differences in hemispheric specialization of cognitive functions as they relate to the dominant cognitive activity of each of the different groups. In view of the contralateral control of the two hemifaces (below the eyes) by the two hemispheres of the brain, the two sides of the face undergo differential muscular development, thus creating facial asymmetry. Other factors, such as gender, also may affect facial asymmetry. Suggestions for further research on facedness are discussed.

Frontal Brain Asymmetry and Willingness to Pay.

PubMed

Ramsøy, Thomas Z; Skov, Martin; Christensen, Maiken K; Stahlhut, Carsten

2018-01-01

Consumers frequently make decisions about how much they are willing to pay (WTP) for specific products and services, but little is known about the neural mechanisms underlying such calculations. In this study, we were interested in testing whether specific brain activation-the asymmetry in engagement of the prefrontal cortex-would be related to consumer choice. Subjects saw products and subsequently decided how much they were willing to pay for each product, while undergoing neuroimaging using electroencephalography. Our results demonstrate that prefrontal asymmetry in the gamma frequency band, and a trend in the beta frequency band that was recorded during product viewing was significantly related to subsequent WTP responses. Frontal asymmetry in the alpha band was not related to WTP decisions. Besides suggesting separate neuropsychological mechanisms of consumer choice, we find that one specific measure-the prefrontal gamma asymmetry-was most strongly related to WTP responses, and was most coupled to the actual decision phase. These findings are discussed in light of the psychology of WTP calculations, and in relation to the recent emergence of consumer neuroscience and neuromarketing.

Asymmetries in visual search for conjunctive targets.

PubMed

Cohen, A

1993-08-01

Asymmetry is demonstrated between conjunctive targets in visual search with no detectable asymmetries between the individual features that compose these targets. Experiment 1 demonstrated this phenomenon for targets composed of color and shape. Experiment 2 and 4 demonstrate this asymmetry for targets composed of size and orientation and for targets composed of contrast level and orientation, respectively. Experiment 3 demonstrates that search rate of individual features cannot predict search rate for conjunctive targets. These results demonstrate the need for 2 levels of representations: one of features and one of conjunction of features. A model related to the modified feature integration theory is proposed to account for these results. The proposed model and other models of visual search are discussed.

Regional cerebral blood flow in childhood autism: a SPET study with SPM evaluation.

PubMed

Burroni, Luca; Orsi, Alessandra; Monti, Lucia; Hayek, Youssef; Rocchi, Raffaele; Vattimo, Angelo G

2008-02-01

To establish a link between rCBF assessed with Tc-ECD SPET and the clinical manifestation of the disease. We performed the study on 11 patients (five girls and six boys; mean age 11.2 years) displaying autistic behaviour and we compared their data with that of an age-matched reference group of eight normal children. A quantitative analysis of rCBF was performed calculating a perfusion index (PI) and an asymmetry index (AI) in each lobe. Images were analysed with statistical parametric mapping software, following the spatial normalization of SPET images for a standard brain. A statistically significant (P=0.003) global reduction of CBF was found in the group of autistic children (PI=1.07+/-0.07) when compared with the reference group (PI=1.25+/-0.12). Moreover, a significant difference was also observed for the right-to-left asymmetry of hemispheric perfusion between the control group and autistic patients (P=0.0085) with a right prevalence greater in autistic (2.90+/-1.68) with respect to normal children (1.12+/-0.49). Our data show a significant decrease of global cerebral perfusion in autistic children in comparison with their normal counterparts and the existence of left-hemispheric dysfunction, especially in the temporo-parietal areas devoted to language and the comprehension of music and sounds. We suggest that these abnormal areas are related to the cognitive impairment observed in autistic children, such as language deficits, impairment of cognitive development and object representation, and abnormal perception and responses to sensory stimuli. Tc-ECD SPET seems to be sensitive in revealing brain blood flow alterations and left-to-right asymmetries, when neuroradiological patterns are normal.

Functional asymmetry of posture and body system regulation

NASA Technical Reports Server (NTRS)

Boloban, V. N.; Otsupok, A. P.

1980-01-01

The manifestation of functional asymmetry during the regulation of an athlete's posture and a system of bodies and its effect on the execution of individual and group acrobatic exercises were studied. Functional asymmetry of posture regulation was recorded in acrobats during the execution of individual and group exercises. It was shown that stability is maintained at the expense of bending and twisting motions. It is important to consider whether the functional asymmetry of posture regulation is left or right sided in making up pairs and groups of acrobats.

Comparison of Cerebral Oximeter and Pulse Oximeter Values in the First 72 Hours in Premature, Asphyctic and Healthy Newborns.

PubMed

Kaya, A; Okur, M; Sal, E; Peker, E; Köstü, M; Tuncer, O; Kırımi, E

2014-12-01

The monitoring of oxygenation is essential for providing patient safety and optimal results. We aimed to determine brain oxygen saturation values in healthy, asphyctic and premature newborns and to compare cerebral oximeter and pulse oximeter values in the first 72 hours of life in neonatal intensive care units. This study was conducted at the neonatal intensive care unit (NICU) of Van Yüzüncü Yil University Research and Administration Hospital. Seventy-five neonatal infants were included in the study (28 asphyxia, 24 premature and 23 mature healthy infants for control group). All infants were studied within the first 72 hours of life. We used a Somanetics 5100C cerebral oximeter (INVOS cerebral/somatic oximeter, Troy, MI, USA). The oxygen saturation information was collected by a Nellcor N-560 pulse oximeter (Nellcor-Puriton Bennet Inc, Pleasanton, CA, USA). In the asphyxia group, the cerebral oximeter average was 76.85 ± 14.1, the pulse oximeter average was 91.86 ± 5.9 and the heart rate average was 139.91 ± 22.3. Among the premature group, the cerebral oximeter average was 79.08 ± 9.04, the pulse oximeter average was 92.01 ± 5.3 and the heart rate average was 135.35 ± 17.03. In the control group, the cerebral oximeter average was 77.56 ± 7.6, the pulse oximeter average was 92.82 ± 3.8 and the heart rate average was 127.04 ± 19.7. Cerebral oximeter is a promising modality in bedside monitoring in neonatal intensive care units. It is complementary to pulse oximeter. It may be used routinely in neonatal intensive care units.

Hand preference and magnetic resonance imaging asymmetries of the central sulcus.

PubMed

Foundas, A L; Hong, K; Leonard, C M; Heilman, K M

1998-04-01

Hand preference is perhaps the most evident behavioral asymmetry observed in humans. Anatomic brain asymmetries that may be associated with hand preference have not been extensively studied, and no clear relationship between asymmetries of the motor system and hand preference have been established. Therefore, using volumetric magnetic resonance imaging methodologies, the surface area of the hand representation was measured along the length of the central sulcus in 15 consistent right- and 15 left-handers matched for age and gender. There was a significant leftward asymmetry of the motor hand area of the precentral gyrus in the right-handers, but no directional asymmetry was found in the left-handers. When asymmetry quotients were computed to determine the distribution of interhemispheric asymmetries, the left motor bank was greater than the right motor bank in 9 of 15 right-handers, the right motor bank was greater than the left motor bank in 3 of 15 right-handers, and the motor banks were equal in 3 of 15 right-handers. In contrast, among left-handers, the left motor bank was greater than the right motor bank in 5 of 15, the right motor bank was greater than the left motor bank in 5 of 15, and the motor banks were equal in 5 of 15. Although no direct measure of motor dexterity and skill was performed, these data suggest that anatomic asymmetries of the motor hand area may be related to hand preference because of the differences in right-handers and left-handers. Furthermore, the predominant leftward asymmetry in right-handers and the random distribution of asymmetries in the left-handers support Annett's right-shift theory. It is unclear, however, whether these asymmetries are the result of preferential hand use or are a reflection of a biologic preference to use one limb over the other.

The association between infantile postural asymmetry and unsettled behaviour in babies.

PubMed

Ellwood, Julie; Ford, Michael; Nicholson, Alf

2017-12-01

Unsettled infant behaviour is a common problem of infancy without known aetiology or clearly effective management. Some manual therapists propose that musculoskeletal dysfunction contributes to unsettled infant behaviour, yet reported improvement following treatment is anecdotal. The infantile postural asymmetry measurement scale is a tool which measures infantile asymmetry, a form of musculoskeletal dysfunction. The first part of the study aimed to investigate its reliability and validity for measuring infantile postural asymmetry. This study also aimed to investigate whether there was an association between infantile postural asymmetry and unsettled infant behaviour and whether an association was mediated by, or confounded with, the demographic variables of age, sex, parity, birth weight and weight gain in 12- to 16-week-old infants. Fifty-eight infants were recruited and a quantitative cross-sectional observational design was used. An association between unsettled behaviour and infantile postural asymmetry was not found. A significant difference between high and low cervical rotation deficit groups for surgency was detected in female babies and needs further examination. Questions remain regarding the construct validity of the infantile postural asymmetry scale. No association between unsettled infant behaviour and infantile postural asymmetry was found in 12- to 16-week-old infants. The influence of sex on the interaction between infantile postural asymmetry and infant behaviour needs further examination. An association between unsettled infant behaviour and infantile postural asymmetry is still unproven. What is known: • Unsettled infant behaviour has a considerable impact on many family situations. • Identifying a definitive cause has been a source of much examination and research. Many different hypotheses have been suggested yet much is still unknown. What is new: • The association between unsettled infant behaviour and infantile postural asymmetry is

Pelvic bone asymmetry in 323 study participants receiving abdominal CT scans.

PubMed

Badii, Maziar; Shin, Sonya; Torreggiani, William C; Jankovic, Bojana; Gustafson, Paul; Munk, Peter L; Esdaile, John M

2003-06-15

Retrospective review of all CT scans of pelvis and abdomen performed at our institution in October and November 2000. To determine the prevalence and extent of radiographic pelvic asymmetry in a population of patients not preselected for having low back pain. Pelvic asymmetry refers to asymmetric positioning of landmarks on the two sides of the pelvis and may have a structural or functional etiology. Pelvic asymmetry can be associated with the presence of true leg length discrepancy, lead to false diagnosis or inaccurate measurement of leg length discrepancy, or itself be independently associated with back pain. Although the prevalence of pelvic asymmetry has been reported in patients with back pain to be 24-91%, its prevalence in the general population is not known. A total of 323 consecutive CT scans of the pelvis/abdomen were assessed for pelvic asymmetry by one of three examiners. Pelvic asymmetry was defined as an unequal distance from the iliac crests to the acetabuli bilaterally, measured on the anteroposterior scout view of the CT scan. Measurements made on 30 randomly selected scans by the three examiners were used to assess interrater reliability of the measurement method. Pelvic asymmetry ranged in magnitude from -11 mm to 7 mm [right pelvis (mm) - left pelvis (mm)]. Pelvic asymmetry was >5 mm in 17 of 323 (5.3%) and >10 mm in 2 of 323 (0.6%) of the subjects; 172 of 323 (53.3%) had a smaller right hemipelvis (mean asymmetry = -3.0 mm). A total of 95 of 323 (29.4%) had a smaller left hemipelvis (mean asymmetry = 2.1 mm). The intraclass correlation coefficient [ICC(2,1)] between the three observers was high (0.91). Pelvic asymmetry of >5 mm was uncommon, with a prevalence of approximately 5% in the population studied. CT scanography was found to be a practical and reliable method for the assessment of suspected pelvic asymmetry.

Relationship Between Muscle Strength Asymmetry and Body Sway in Older Adults.

PubMed

Koda, Hitoshi; Kai, Yoshihiro; Murata, Shin; Osugi, Hironori; Anami, Kunihiko; Fukumoto, Takahiko; Imagita, Hidetaka

2018-05-31

The purpose of this study was to investigate the relationship between muscle strength asymmetry and body sway while walking. We studied 63 older adult women. Strong side and weak side of knee extension strength, toe grip strength, hand grip strength, and body sway while walking were measured. The relationship between muscle strength asymmetry for each muscle and body sway while walking was evaluated using Pearson's correlation coefficient. Regarding the muscles recognized to have significant correlation with body sway, the asymmetry cutoff value causing an increased sway was calculated. Toe grip strength asymmetry was significantly correlated with body sway. Toe grip strength asymmetry causing an increased body sway had a cutoff value of 23.5%. Our findings suggest toe grip strength asymmetry may be a target for improving gait stability.

The validity of individual frontal alpha asymmetry EEG neurofeedback

PubMed Central

Quaedflieg, C. W. E. M.; Smulders, F. T. Y.; Meyer, T.; Peeters, F.; Merckelbach, H.; Smeets, T.

2016-01-01

Frontal asymmetry in alpha oscillations is assumed to be associated with psychopathology and individual differences in emotional responding. Brain-activity-based feedback is a promising tool for the modulation of cortical activity. Here, we validated a neurofeedback protocol designed to change relative frontal asymmetry based on individual alpha peak frequencies, including real-time average referencing and eye-correction. Participants (N = 60) were randomly assigned to a right, left or placebo neurofeedback group. Results show a difference in trainability between groups, with a linear change in frontal alpha asymmetry over time for the right neurofeedback group during rest. Moreover, the asymmetry changes in the right group were frequency and location specific, even though trainability did not persist at 1 week and 1 month follow-ups. On the behavioral level, subjective stress on the second test day was reduced in the left and placebo neurofeedback groups, but not in the right neurofeedback group. We found individual differences in trainability that were dependent on training group, with participants in the right neurofeedback group being more likely to change their frontal asymmetry in the desired direction. Individual differences in trainability were also reflected in the ability to change frontal asymmetry during the feedback. PMID:26163671

Gaussian quantum steering and its asymmetry in curved spacetime

NASA Astrophysics Data System (ADS)

Wang, Jieci; Cao, Haixin; Jing, Jiliang; Fan, Heng

2016-06-01

We study Gaussian quantum steering and its asymmetry in the background of a Schwarzschild black hole. We present a Gaussian channel description of quantum state evolution under the influence of Hawking radiation. We find that thermal noise introduced by the Hawking effect will destroy the steerability between an inertial observer Alice and an accelerated observer Bob who hovers outside the event horizon, while it generates steerability between Bob and a hypothetical observer anti-Bob inside the event horizon. Unlike entanglement behaviors in curved spacetime, here the steering from Alice to Bob suffers from a "sudden death" and the steering from anti-Bob to Bob experiences a "sudden birth" with increasing Hawking temperature. We also find that the Gaussian steering is always asymmetric and the maximum steering asymmetry cannot exceed ln 2 , which means the state never evolves to an extremal asymmetry state. Furthermore, we obtain the parameter settings that maximize steering asymmetry and find that (i) s =arccosh cosh/2r 1 -sinh2r is the critical point of steering asymmetry and (ii) the attainment of maximal steering asymmetry indicates the transition between one-way steerability and both-way steerability for the two-mode Gaussian state under the influence of Hawking radiation.

Cerebral ischemia and neuroregeneration

PubMed Central

Lee, Reggie H. C.; Lee, Michelle H. H.; Wu, Celeste Y. C.; Couto e Silva, Alexandre; Possoit, Harlee E.; Hsieh, Tsung-Han; Minagar, Alireza; Lin, Hung Wen

2018-01-01

Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke (a form of cerebral ischemia)-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics (i.e., tissue plasminogen activator) and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies against stroke/cerebral ischemia are urgently needed. Here, we discuss the possible mechanism(s) underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies (i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase C isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells) as it relates to cerebral ischemia. PMID:29623912

Evaluation of Limb Load Asymmetry Using Two New Mathematical Models

PubMed Central

Kumar, Senthil NS; Omar, Baharudin; Joseph, Leonard H.; Htwe, Ohnmar; Jagannathan, K.; Hamdan, Nor M Y; Rajalakshmi, D.

2015-01-01

Quantitative measurement of limb loading is important in orthopedic and neurological rehabilitation. In current practice, mathematical models such as Symmetry index (SI), Symmetry ratio (SR), and Symmetry angle (SA) are used to quantify limb loading asymmetry. Literatures have identified certain limitations with the above mathematical models. Hence this study presents two new mathematical models Modified symmetry index (MSI) and Limb loading error (LLE) that would address these limitations. Furthermore, the current mathematical models were compared against the new model with the goal of achieving a better model. This study uses hypothetical data to simulate an algorithmic preliminary computational measure to perform with all numerical possibilities of even and uneven limb loading that can occur in human legs. Descriptive statistics are used to interpret the limb loading patterns: symmetry, asymmetry and maximum asymmetry. The five mathematical models were similar in analyzing symmetry between limbs. However, for asymmetry and maximum asymmetry data, the SA and SR values do not give any meaningful interpretation, and SI gives an inflated value. The MSI and LLE are direct, easy to interpret and identify the loading patterns with the side of asymmetry. The new models are notable as they quantify the amount and side of asymmetry under different loading patterns. PMID:25716372

Shifting brain asymmetry: the link between meditation and structural lateralization

PubMed Central

Kurth, Florian; MacKenzie-Graham, Allan; Toga, Arthur W.

2015-01-01

Previous studies have revealed an increased fractional anisotropy and greater thickness in the anterior parts of the corpus callosum in meditation practitioners compared with control subjects. Altered callosal features may be associated with an altered inter-hemispheric integration and the degree of brain asymmetry may also be shifted in meditation practitioners. Therefore, we investigated differences in gray matter asymmetry as well as correlations between gray matter asymmetry and years of meditation practice in 50 long-term meditators and 50 controls. We detected a decreased rightward asymmetry in the precuneus in meditators compared with controls. In addition, we observed that a stronger leftward asymmetry near the posterior intraparietal sulcus was positively associated with the number of meditation practice years. In a further exploratory analysis, we observed that a stronger rightward asymmetry in the pregenual cingulate cortex was negatively associated with the number of practice years. The group difference within the precuneus, as well as the positive correlations with meditation years in the pregenual cingulate cortex, suggests an adaptation of the default mode network in meditators. The positive correlation between meditation practice years and asymmetry near the posterior intraparietal sulcus may suggest that meditation is accompanied by changes in attention processing. PMID:24643652

Amplitude and polarization asymmetries in a ring laser

NASA Technical Reports Server (NTRS)

Campbell, L. L.; Buholz, N. E.

1971-01-01

Asymmetric amplitude effects between the oppositely directed traveling waves in a He-Ne ring laser are analyzed both theoretically and experimentally. These effects make it possible to detect angular orientations of an inner-cavity bar with respect to the plane of the ring cavity. The amplitude asymmetries occur when a birefringent bar is placed in the three-mirror ring cavity, and an axial magnetic field is applied to the active medium. A simplified theoretical analysis is performed by using a first order perturbation theory to derive an expression for the polarization of the active medium, and a set of self-consistent equations are derived to predict threshold conditions. Polarization asymmetries between the oppositely directed waves are also predicted. Amplitude asymmetries similar in nature to those predicted at threshold occur when the laser is operating in 12-15 free-running modes, and polarization asymmetry occurs simultaneously.

Characterization of Asymmetry in Magnetoacoustic Emission Burst by Numerical Processes

NASA Technical Reports Server (NTRS)

Namkung, M.; Fulton, J. P.; Wincheski, B.; DeNale, R.

1991-01-01

It has been well known that the pattern of the magnetoacoustic emission (MAE) burst observed during the sweep over one half-cycle of the hysteresis loop becomes asymmetric depending on the strength of the magnetic domain wall-defect interaction and the state of residual stresses in a ferromagnet. The ascending asymmetry due to the former has been observed at a very low frequency (.7 Hz) of applied AC magnetic field at a given amplitude. The descending asymmetry due to uniaxial compressive stress has been typically observed at the AC applied magnetic field frequency of 20 Hz. The physical interpretation of both types of asymmetry has been well established. It is, however, necessary to perform investigations of the dependence of asymmetry on externally controlled parameters such as the amplitude and frequency of the AC applied magnetic fields. The purpose of the present study is therefore to devise a mathematical means that describes the degree of asymmetry of the MAE burst and apply this scheme to investigate the AC magnetic field amplitude dependence of the asymmetry.

Cortical asymmetries in unaffected siblings of patients with obsessive-compulsive disorder.

PubMed

Peng, Ziwen; Li, Gang; Shi, Feng; Shi, Changzheng; Yang, Qiong; Chan, Raymond C K; Shen, Dinggang

2015-12-30

Obsessive-compulsive disorder (OCD) is considered to be associated with atypical brain asymmetry. However, no study has examined the asymmetry in OCD from the perspective of cortical morphometry. This study is aimed to describe the characteristics of cortical asymmetry in OCD patients, and to investigate whether these features exist in their unaffected siblings - a vital step in identifying putative endophenotypes for OCD. A total of 48 subjects (16 OCD patients, 16 unaffected siblings, and 16 matched controls) were recruited who had complete magnetic resonance imaging scans. Left-right hemispheric asymmetries of cortical thickness were measured using a surface-based threshold-free cluster enhancement method. OCD patients and siblings both showed leftward asymmetries of cortical thickness in the anterior cingulate cortex (ACC), which showed a significant positive correlation with compulsive subscale scores. In addition, siblings and healthy controls showed significantly decreased leftward asymmetries in the orbitofrontal cortex (OFC), and the decreased leftward bias in the OFC was accompanied by lower scales on the Yale-Brown Obsessive-Compulsive Scale. To sum up, leftward asymmetries of cortical thickness in the ACC may represent an endophenotype of increased hereditary risk for OCD, while decreased leftward asymmetries of cortical thickness in the OFC may represent a protective factor. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The role of frontal EEG asymmetry in post-traumatic stress disorder.

PubMed

Meyer, Thomas; Smeets, Tom; Giesbrecht, Timo; Quaedflieg, Conny W E M; Smulders, Fren T Y; Meijer, Ewout H; Merckelbach, Harald L G J

2015-05-01

Frontal alpha asymmetry, a biomarker derived from electroencephalography (EEG) recordings, has often been associated with psychological adjustment, with more left-sided frontal activity predicting approach motivation and lower levels of depression and anxiety. This suggests high relevance to post-traumatic stress disorder (PTSD), a disorder comprising anxiety and dysphoria symptoms. We review this relationship and show that frontal asymmetry can be plausibly linked to neuropsychological abnormalities seen in PTSD. However, surprisingly few studies (k = 8) have directly addressed frontal asymmetry in PTSD, mostly reporting that trait frontal asymmetry has little (if any) predictive value. Meanwhile, preliminary evidence suggest that state-dependent asymmetry during trauma-relevant stimulation distinguishes PTSD patients from resilient individuals. Thus, exploring links between provocation-induced EEG asymmetry and PTSD appears particularly promising. Additionally, we recommend more fine-grained analyses into PTSD symptom clusters in relation to frontal asymmetry. Finally, we highlight hypotheses that may guide future research and help to fully apprehend the practical and theoretical relevance of this biological marker. Copyright © 2015 Elsevier B.V. All rights reserved.

New tuning method of the low-mode asymmetry for ignition capsule implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Jianfa, E-mail: gu-jianfa@iapcm.ac.cn; Dai, Zhensheng; Zou, Shiyang

2015-12-15

In the deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility, the hot spot and the surrounding main fuel layer show obvious P2 asymmetries. This may be caused by the large positive P2 radiation flux asymmetry during the peak pulse resulting form the poor propagation of the inner laser beam in the gas-filled hohlraum. The symmetry evolution of ignition capsule implosions is investigated by applying P2 radiation flux asymmetries during different time intervals. A series of two-dimensional simulation results show that a positive P2 flux asymmetry during the peak pulse results in a positive P2 shell ρR asymmetry;more » while an early time positive P2 flux asymmetry causes a negative P2 in the fuel ρR shape. The opposite evolution behavior of shell ρR asymmetry is used to develop a new tuning method to correct the radiation flux asymmetry during the peak pulse by adding a compensating same-phased P2 drive asymmetry during the early time. The significant improvements of the shell ρR symmetry, hot spot shape, hot spot internal energy, and neutron yield indicate that the tuning method is quite effective. The similar tuning method can also be used to control the early time drive asymmetries.« less

The functional and structural asymmetries of the superior temporal sulcus.

PubMed

Specht, Karsten; Wigglesworth, Philip

2018-02-01

The superior temporal sulcus (STS) is an anatomical structure that increasingly interests researchers. This structure appears to receive multisensory input and is involved in several perceptual and cognitive core functions, such as speech perception, audiovisual integration, (biological) motion processing and theory of mind capacities. In addition, the superior temporal sulcus is not only one of the longest sulci of the brain, but it also shows marked functional and structural asymmetries, some of which have only been found in humans. To explore the functional-structural relationships of these asymmetries in more detail, this study combines functional and structural magnetic resonance imaging. Using a speech perception task, an audiovisual integration task, and a theory of mind task, this study again demonstrated an involvement of the STS in these processes, with an expected strong leftward asymmetry for the speech perception task. Furthermore, this study confirmed the earlier described, human-specific asymmetries, namely that the left STS is longer than the right STS and that the right STS is deeper than the left STS. However, this study did not find any relationship between these structural asymmetries and the detected brain activations or their functional asymmetries. This can, on the other hand, give further support to the notion that the structural asymmetry of the STS is not directly related to the functional asymmetry of the speech perception and the language system as a whole, but that it may have other causes and functions. © 2018 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Cerebral Palsy

MedlinePlus

Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

Auxin asymmetry during gravitropism by tomato hypocotyls

NASA Technical Reports Server (NTRS)

Harrison, M. A.; Pickard, B. G.

1989-01-01

Gravitropic asymmetry of auxin was observed in hypocotyls of tomato (Lycopersicon esculentum Mill.) soon after horizontal placement: the ratio of apically supplied [3H]IAA collected from the lower sides to that from the upper sides was about 1.4 between 5 and 10 minutes. This was adequately early to account for the beginning of curvature. The auxin asymmetry ratio rose to about 2.5 between 20 and 25 minutes, and to 3.5 during the main phase of curvature. This compares reasonably well with the roughly 3.9 ratio for elongation on the lower side to elongation on the upper side that is the basis for the curvature. These data extend evidence that the Went-Cholodny theory for the mediation of tropisms is valid for dicot stems. Also consistent with the theory, an auxin asymmetry ratio of 2.5 was observed when wrong-way gravitropic curvature developed following application of a high level of auxin. In addition to reversing the asymmetry of elongation, the large supplement of auxin resulted in lower net elongation. Previous data established that ethylene is not involved in this decrease of growth as a function of increasing level of auxin.

[Presurgical orthodontics for facial asymmetry].

PubMed

Labarrère, H

2003-03-01

As with the treatment of all facial deformities, orthodontic pre-surgical preparation for facial asymmetry should aim at correcting severe occlusal discrepancies not solely on the basis of a narrow occlusal analysis but also in a way that will not disturb the proposed surgical protocol. In addition, facial asymmetries require specific adjustments, difficult to derive and to apply because of their inherent atypical morphological orientation of both alveolar and basal bony support. Three treated cases illustrate different solutions to problems posed by pathological torque: this torque must be considered with respect to proposed surgical changes, within the framework of their limitations and their possible contra-indications.

Prefrontal brain asymmetry and aggression in imprisoned violent offenders.

PubMed

Keune, Philipp M; van der Heiden, Linda; Várkuti, Bálint; Konicar, Lilian; Veit, Ralf; Birbaumer, Niels

2012-05-02

Anterior brain asymmetry, assessed through the alpha and beta band in resting-state electroencephalogram (EEG) is associated with approach-related behavioral dispositions, particularly with aggression in the general population. To date, the association between frontal asymmetry and aggression has not been examined in highly aggressive groups. We examined the topographic characteristics of alpha and beta activity, the relation of both asymmetry metrics to trait aggression, and whether alpha asymmetry was extreme in anterior regions according to clinical standards in a group of imprisoned violent offenders. As expected, these individuals were characterized by stronger right than left-hemispheric alpha activity, which was putatively extreme in anterior regions in one third of the cases. We also report that in line with observations made in the general population, aggression was associated with stronger right-frontal alpha activity in these violent individuals. This suggests that frontal alpha asymmetry, as a correlate of trait aggression, might be utilizable as an outcome measure in studies which assess the effects of anti-aggressiveness training in violent offenders. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Frobenius-norm-based measures of quantum coherence and asymmetry

PubMed Central

Yao, Yao; Dong, G. H.; Xiao, Xing; Sun, C. P.

2016-01-01

We formulate the Frobenius-norm-based measures for quantum coherence and asymmetry respectively. In contrast to the resource theory of coherence and asymmetry, we construct a natural measure of quantum coherence inspired from optical coherence theory while the group theoretical approach is employed to quantify the asymmetry of quantum states. Besides their simple structures and explicit physical meanings, we observe that these quantities are intimately related to the purity (or linear entropy) of the corresponding quantum states. Remarkably, we demonstrate that the proposed coherence quantifier is not only a measure of mixedness, but also an intrinsic (basis-independent) quantification of quantum coherence contained in quantum states, which can also be viewed as a normalized version of Brukner-Zeilinger invariant information. In our context, the asymmetry of N-qubit quantum systems is considered under local independent and collective transformations. In- triguingly, it is illustrated that the collective effect has a significant impact on the asymmetry measure, and quantum correlation between subsystems plays a non-negligible role in this circumstance. PMID:27558009

Parity-violating electroweak asymmetry in e→ p scattering

NASA Astrophysics Data System (ADS)

Aniol, K. A.; Armstrong, D. S.; Averett, T.; Baylac, M.; Burtin, E.; Calarco, J.; Cates, G. D.; Cavata, C.; Chai, Z.; Chang, C. C.; Chen, J.-P.; Chudakov, E.; Cisbani, E.; Coman, M.; Dale, D.; Deur, A.; Djawotho, P.; Epstein, M. B.; Escoffier, S.; Ewell, L.; Falletto, N.; Finn, J. M.; Fissum, K.; Fleck, A.; Frois, B.; Frullani, S.; Gao, J.; Garibaldi, F.; Gasparian, A.; Gerstner, G. M.; Gilman, R.; Glamazdin, A.; Gomez, J.; Gorbenko, V.; Hansen, O.; Hersman, F.; Higinbotham, D. W.; Holmes, R.; Holtrop, M.; Humensky, T. B.; Incerti, S.; Iodice, M.; de Jager, C. W.; Jardillier, J.; Jiang, X.; Jones, M. K.; Jorda, J.; Jutier, C.; Kahl, W.; Kelly, J. J.; Kim, D. H.; Kim, M.-J.; Kim, M. S.; Kominis, I.; Kooijman, E.; Kramer, K.; Kumar, K. S.; Kuss, M.; Lerose, J.; de Leo, R.; Leuschner, M.; Lhuillier, D.; Liang, M.; Liyanage, N.; Lourie, R.; Madey, R.; Malov, S.; Margaziotis, D. J.; Marie, F.; Markowitz, P.; Martino, J.; Mastromarino, P.; McCormick, K.; McIntyre, J.; Meziani, Z.-E.; Michaels, R.; Milbrath, B.; Miller, G. W.; Mitchell, J.; Morand, L.; Neyret, D.; Pedrisat, C.; Petratos, G. G.; Pomatsalyuk, R.; Price, J. S.; Prout, D.; Punjabi, V.; Pussieux, T.; Quéméner, G.; Ransome, R. D.; Relyea, D.; Roblin, Y.; Roche, J.; Rutledge, G. A.; Rutt, P. M.; Rvachev, M.; Sabatie, F.; Saha, A.; Souder, P. A.; Spradlin, M.; Strauch, S.; Suleiman, R.; Templon, J.; Teresawa, T.; Thompson, J.; Tieulent, R.; Todor, L.; Tonguc, B. T.; Ulmer, P. E.; Urciuoli, G. M.; Vlahovic, B.; Wijesooriya, K.; Wilson, R.; Wojtsekhowski, B.; Woo, R.; Xu, W.; Younus, I.; Zhang, C.

2004-06-01

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from protons. Significant contributions to this asymmetry could arise from the contributions of strange form factors in the nucleon. The measured asymmetry is A= -15.05±0.98 (stat) ±0.56 (syst) ppm at the kinematic point < θlab > =12.3° and < Q2 > =0.477 (GeV/c)2 . Based on these data as well as data on electromagnetic form factors, we extract the linear combination of strange form factors GsE +0.392 GsM = 0.014±0.020±0.010 , where the first error arises from this experiment and the second arises from the electromagnetic form factor data. This paper provides a full description of the special experimental techniques employed for precisely measuring the small asymmetry, including the first use of a strained GaAs crystal and a laser-Compton polarimeter in a fixed target parity-violation experiment.

Using ground reaction force to predict knee kinetic asymmetry following anterior cruciate ligament reconstruction.

PubMed

Dai, B; Butler, R J; Garrett, W E; Queen, R M

2014-12-01

Asymmetries in sagittal plane knee kinetics have been identified as a risk factor for anterior cruciate ligament (ACL) re-injury. Clinical tools are needed to identify the asymmetries. This study examined the relationships between knee kinetic asymmetries and ground reaction force (GRF) asymmetries during athletic tasks in adolescent patients following ACL reconstruction (ACL-R). Kinematic and GRF data were collected during a stop-jump task and a side-cutting task for 23 patients. Asymmetry indices between the surgical and non-surgical limbs were calculated for GRF and knee kinetic variables. For the stop-jump task, knee kinetics asymmetry indices were correlated with all GRF asymmetry indices (P < 0.05), except for loading rate. Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2)  ≥ 0.78, P < 0.01) asymmetry indices. For the side-cutting tasks, knee kinetic asymmetry indices were correlated with the peak propulsion vertical GRF and vertical GRF impulse asymmetry indices (P < 0.05). Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2)  ≥ 0.55, P < 0.01) asymmetry indices. The vertical GRF asymmetries may be a viable surrogate for knee kinetic asymmetries and therefore may assist in optimizing rehabilitation outcomes and minimizing re-injury rates. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

microRNA function in left-right neuronal asymmetry: perspectives from C. elegans.

PubMed

Alqadah, Amel; Hsieh, Yi-Wen; Chuang, Chiou-Fen

2013-09-23

Left-right asymmetry in anatomical structures and functions of the nervous system is present throughout the animal kingdom. For example, language centers are localized in the left side of the human brain, while spatial recognition functions are found in the right hemisphere in the majority of the population. Disruption of asymmetry in the nervous system is correlated with neurological disorders. Although anatomical and functional asymmetries are observed in mammalian nervous systems, it has been a challenge to identify the molecular basis of these asymmetries. C. elegans has emerged as a prime model organism to investigate molecular asymmetries in the nervous system, as it has been shown to display functional asymmetries clearly correlated to asymmetric distribution and regulation of biologically relevant molecules. Small non-coding RNAs have been recently implicated in various aspects of neural development. Here, we review cases in which microRNAs are crucial for establishing left-right asymmetries in the C. elegans nervous system. These studies may provide insight into how molecular and functional asymmetries are established in the human brain.

Motor Behavior Reflects Reduced Hemispheric Asymmetry in the Psychosis Risk Period

PubMed Central

Dean, Derek J.; Orr, Joseph M.; Newberry, Raeana E.; Mittal, Vijay A.

2015-01-01

Background A body of work focusing on brain connectivity, language dominance, and motor laterality research suggests reduced hemispheric asymmetry is a core feature in schizophrenia. However, there is little consensus about whether reduced dominance is present in those at ultrahigh risk (UHR) for psychosis. Methods A total of 94 demonstrated right-handed neuroleptic free participants (38 UHR and 56 matched healthy controls) were assessed with structured clinical interviews and completed an innovative handwriting task using a digital tablet computer. A laterality quotient (LQ) was calculated using kinematic variables from the participant’s left and right hands. A subset of the sample (26 UHR and 29 controls) returned after 12-months to complete clinical interviews in order to examine relationships between handwriting laterality and progression of psychosis risk symptoms. Results The UHR group showed decreased dextrality compared to healthy controls. At the 12-month follow-up, decreased dextrality accounted for 8% of the variance in worsened positive symptoms within the UHR group. Conclusion The current results suggest that disrupted cerebral dominance is also present in the ultrahigh risk period and that decreased dextrality may serve as a novel biomarker for the progression of psychosis risk. PMID:26492987

[Etiology of cerebral palsy].

PubMed

Jaisle, F

1996-01-01

The "perinatal asphyxia" is regarded to be one of the causes of cerebral palsy, though in the very most of the children with cerebral palsy there is found no hypoxia during labour. It should be mentioned, that the definition of "perinatal" and "asphyxia" neither are unic nor concret. And also there is no correlation between nonreassuring fetal heart rate patterns and acidosis in fetal blood with the incidence of cerebral palsy. Numerous studies in pregnant animals failed in proving an acute intrapartal hypoxia to be the origin of the cerebral palsy. Myers (1975) describes four patterns of anatomic brain damage after different injuries. Only his so called oligo-acidotic hypoxia, which is protracted and lasts over a longer time is leading to brain injury, which can be regarded in analogy to the injury of children with cerebral palsy. Summarising the update publications about the causes of cerebral palsy and the studies in pregnant animals there is no evidence that hypoxia during labour may be the cause of cerebral palsy. There is a great probability of a pre(and post-)natal origin of brain injury (for instance a periventricular leucomalacia found after birth) which leads to cerebral palsy. Short after labour signs of a so called "asphyxia" may occur in addition to this preexisting injury and misrepresent the cause of cerebral palsy. Finally the prepartal injury may cause both: Cerebral palsy and hypoxia.

Left-right leaf asymmetry in decussate and distichous phyllotactic systems.

PubMed

Martinez, Ciera C; Chitwood, Daniel H; Smith, Richard S; Sinha, Neelima R

2016-12-19

Leaves in plants with spiral phyllotaxy exhibit directional asymmetries, such that all the leaves originating from a meristem of a particular chirality are similarly asymmetric relative to each other. Models of auxin flux capable of recapitulating spiral phyllotaxis predict handed auxin asymmetries in initiating leaf primordia with empirically verifiable effects on superficially bilaterally symmetric leaves. Here, we extend a similar analysis of leaf asymmetry to decussate and distichous phyllotaxy. We found that our simulation models of these two patterns predicted mirrored asymmetries in auxin distribution in leaf primordia pairs. To empirically verify the morphological consequences of asymmetric auxin distribution, we analysed the morphology of a tomato sister-of-pin-formed1a (sopin1a) mutant, entire-2, in which spiral phyllotaxy consistently transitions to a decussate state. Shifts in the displacement of leaflets on the left and right sides of entire-2 leaf pairs mirror each other, corroborating predicted model results. We then analyse the shape of more than 800 common ivy (Hedera helix) and more than 3000 grapevine (Vitis and Ampelopsis spp.) leaf pairs and find statistical enrichment of predicted mirrored asymmetries. Our results demonstrate that left-right auxin asymmetries in models of decussate and distichous phyllotaxy successfully predict mirrored asymmetric leaf morphologies in superficially symmetric leaves.This article is part of the themed issue 'Provocative questions in left-right asymmetry'. © 2016 The Author(s).

Magnetic fields and chiral asymmetry in the early hot universe

NASA Astrophysics Data System (ADS)

Sydorenko, Maksym; Tomalak, Oleksandr; Shtanov, Yuri

2016-10-01

In this paper, we study analytically the process of external generation and subsequent free evolution of the lepton chiral asymmetry and helical magnetic fields in the early hot universe. This process is known to be affected by the Abelian anomaly of the electroweak gauge interactions. As a consequence, chiral asymmetry in the fermion distribution generates magnetic fields of non-zero helicity, and vice versa. We take into account the presence of thermal bath, which serves as a seed for the development of instability in magnetic field in the presence of externally generated lepton chiral asymmetry. The developed helical magnetic field and lepton chiral asymmetry support each other, considerably prolonging their mutual existence, in the process of `inverse cascade' transferring magnetic-field power from small to large spatial scales. For cosmologically interesting initial conditions, the chiral asymmetry and the energy density of helical magnetic field are shown to evolve by scaling laws, effectively depending on a single combined variable. In this case, the late-time asymptotics of the conformal chiral chemical potential reproduces the universal scaling law previously found in the literature for the system under consideration. This regime is terminated at lower temperatures because of scattering of electrons with chirality change, which exponentially washes out chiral asymmetry. We derive an expression for the termination temperature as a function of the chiral asymmetry and energy density of helical magnetic field.

Visual search asymmetries within color-coded and intensity-coded displays.

PubMed

Yamani, Yusuke; McCarley, Jason S

2010-06-01

Color and intensity coding provide perceptual cues to segregate categories of objects within a visual display, allowing operators to search more efficiently for needed information. Even within a perceptually distinct subset of display elements, however, it may often be useful to prioritize items representing urgent or task-critical information. The design of symbology to produce search asymmetries (Treisman & Souther, 1985) offers a potential technique for doing this, but it is not obvious from existing models of search that an asymmetry observed in the absence of extraneous visual stimuli will persist within a complex color- or intensity-coded display. To address this issue, in the current study we measured the strength of a visual search asymmetry within displays containing color- or intensity-coded extraneous items. The asymmetry persisted strongly in the presence of extraneous items that were drawn in a different color (Experiment 1) or a lower contrast (Experiment 2) than the search-relevant items, with the targets favored by the search asymmetry producing highly efficient search. The asymmetry was attenuated but not eliminated when extraneous items were drawn in a higher contrast than search-relevant items (Experiment 3). Results imply that the coding of symbology to exploit visual search asymmetries can facilitate visual search for high-priority items even within color- or intensity-coded displays. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Shifting brain asymmetry: the link between meditation and structural lateralization.

PubMed

Kurth, Florian; MacKenzie-Graham, Allan; Toga, Arthur W; Luders, Eileen

2015-01-01

Previous studies have revealed an increased fractional anisotropy and greater thickness in the anterior parts of the corpus callosum in meditation practitioners compared with control subjects. Altered callosal features may be associated with an altered inter-hemispheric integration and the degree of brain asymmetry may also be shifted in meditation practitioners. Therefore, we investigated differences in gray matter asymmetry as well as correlations between gray matter asymmetry and years of meditation practice in 50 long-term meditators and 50 controls. We detected a decreased rightward asymmetry in the precuneus in meditators compared with controls. In addition, we observed that a stronger leftward asymmetry near the posterior intraparietal sulcus was positively associated with the number of meditation practice years. In a further exploratory analysis, we observed that a stronger rightward asymmetry in the pregenual cingulate cortex was negatively associated with the number of practice years. The group difference within the precuneus, as well as the positive correlations with meditation years in the pregenual cingulate cortex, suggests an adaptation of the default mode network in meditators. The positive correlation between meditation practice years and asymmetry near the posterior intraparietal sulcus may suggest that meditation is accompanied by changes in attention processing. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Short-term tidal asymmetry inversion in a macrotidal estuary (Beira, Mozambique)

NASA Astrophysics Data System (ADS)

Nzualo, Teodósio N. M.; Gallo, Marcos N.; Vinzon, Susana B.

2018-05-01

The distortion of the tide in estuaries, bays and coastal areas is the result of the generation of overtides due to the non-linear effects associated with friction, advection, and the finite effects of the tidal amplitude in shallow waters. The Beira estuary is classified as macrotidal, with a large ratio of S2/M2. Typical tides ranges from 6 m and 0.8 m, during springs and neaps tides, respectively. As a consequence of this large fortnightly tidal amplitude difference and the estuarine morphology, asymmetry inversions occur. Two types of tidal asymmetries were investigated in this paper, one considering tidal duration asymmetry (time difference between rising and falling tide) and the other, related to tidal velocity asymmetry (unequal magnitudes of flood and ebb peaks currents). In the Beira estuary when we examine the tidal duration asymmetry, flood dominance is observed during spring tide periods (negative time difference between rising and falling tide), while ebb dominance appears during neap tides (positive time difference between rising and falling tide). A 2DH hydrodynamic model was implemented to analyze this asymmetry inversion. The model was calibrated with water-level data measured at the Port of Beira and current data measured along the estuary. The model was run for different scenarios considering tidal constituents at the ocean boundary, river discharge and the morphology of the estuary. River discharge did not show significant effects on the tidal duration asymmetry. Through comparison of the scenarios, it was shown that the incoming ocean tide at the boundary has an ebb-dominant asymmetry, changing to flood-dominant only during spring tides due to the effect of shoaling and friction within the estuary. During neap tides, the propagation occurs mainly in the channels, and ebb dominance remains. The interplay between the estuary morphodynamics was thus identified and the relation between tidal duration asymmetry and tidal velocity asymmetry was

The validity of individual frontal alpha asymmetry EEG neurofeedback.

PubMed

Quaedflieg, C W E M; Smulders, F T Y; Meyer, T; Peeters, F; Merckelbach, H; Smeets, T

2016-01-01

Frontal asymmetry in alpha oscillations is assumed to be associated with psychopathology and individual differences in emotional responding. Brain-activity-based feedback is a promising tool for the modulation of cortical activity. Here, we validated a neurofeedback protocol designed to change relative frontal asymmetry based on individual alpha peak frequencies, including real-time average referencing and eye-correction. Participants (N = 60) were randomly assigned to a right, left or placebo neurofeedback group. Results show a difference in trainability between groups, with a linear change in frontal alpha asymmetry over time for the right neurofeedback group during rest. Moreover, the asymmetry changes in the right group were frequency and location specific, even though trainability did not persist at 1 week and 1 month follow-ups. On the behavioral level, subjective stress on the second test day was reduced in the left and placebo neurofeedback groups, but not in the right neurofeedback group. We found individual differences in trainability that were dependent on training group, with participants in the right neurofeedback group being more likely to change their frontal asymmetry in the desired direction. Individual differences in trainability were also reflected in the ability to change frontal asymmetry during the feedback. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Genetic modification of cerebral arterial wall: implications for prevention and treatment of cerebral vasospasm.

PubMed

Vijay, Anantha; Santhanam, R; Katusic, Zvonimir S

2006-10-01

Genetic modification of cerebral vessels represents a promising and novel approach for prevention and/or treatment of various cerebral vascular disorders, including cerebral vasospasm. In this review, we focus on the current understanding of the use of gene transfer to the cerebral arteries for prevention and/or treatment of cerebral vasospasm following subarachnoid hemorrhage (SAH). We also discuss the recent developments in vascular therapeutics, involving the autologous use of progenitor cells for repair of damaged vessels, as well as a cell-based gene delivery approach for the prevention and treatment of cerebral vasospasm.

Automated measurement of vocal fold vibratory asymmetry from high-speed videoendoscopy recordings.

PubMed

Mehta, Daryush D; Deliyski, Dimitar D; Quatieri, Thomas F; Hillman, Robert E

2011-02-01

In prior work, a manually derived measure of vocal fold vibratory phase asymmetry correlated to varying degrees with visual judgments made from laryngeal high-speed videoendoscopy (HSV) recordings. This investigation extended this work by establishing an automated HSV-based framework to quantify 3 categories of vocal fold vibratory asymmetry. HSV-based analysis provided for cycle-to-cycle estimates of left-right phase asymmetry, left-right amplitude asymmetry, and axis shift during glottal closure for 52 speakers with no vocal pathology producing comfortable and pressed phonation. An initial cross-validation of the automated left-right phase asymmetry measure was performed by correlating the measure with other objective and subjective assessments of phase asymmetry. Vocal fold vibratory asymmetry was exhibited to a similar extent in both comfortable and pressed phonations. The automated measure of left-right phase asymmetry strongly correlated with manually derived measures and moderately correlated with visual-perceptual ratings. Correlations with the visual-perceptual ratings remained relatively consistent as the automated measure was derived from kymograms taken at different glottal locations. An automated HSV-based framework for the quantification of vocal fold vibratory asymmetry was developed and initially validated. This framework serves as a platform for investigating relationships between vocal fold tissue motion and acoustic measures of voice function.

Ear asymmetries in middle-ear, cochlear, and brainstem responses in human infants

PubMed Central

Keefe, Douglas H.; Gorga, Michael P.; Jesteadt, Walt; Smith, Lynette M.

2008-01-01

In 2004, Sininger and Cone-Wesson examined asymmetries in the signal-to-noise ratio (SNR) of otoacoustic emissions (OAE) in infants, reporting that distortion-product (DP)OAE SNR was larger in the left ear, whereas transient-evoked (TE)OAE SNR was larger in the right. They proposed that cochlear and brainstem asymmetries facilitate development of brain-hemispheric specialization for sound processing. Similarly, in 2006 Sininger and Cone-Wesson described ear asymmetries mainly favoring the right ear in infant auditory brainstem responses (ABRs). The present study analyzed 2640 infant responses to further explore these effects. Ear differences in OAE SNR, signal, and noise were evaluated separately and across frequencies (1.5, 2, 3, and 4 kHz), and ABR asymmetries were compared with cochlear asymmetries. Analyses of ear-canal reflectance and admittance showed that asymmetries in middle-ear functioning did not explain cochlear and brainstem asymmetries. Current results are consistent with earlier studies showing right-ear dominance for TEOAE and ABR. Noise levels were higher in the right ear for OAEs and ABRs, causing ear asymmetries in SNR to differ from those in signal level. No left-ear dominance for DPOAE signal was observed. These results do not support a theory that ear asymmetries in cochlear processing mimic hemispheric brain specialization for auditory processing. PMID:18345839

Crossed asymmetry in Russell-Silver syndrome.

PubMed Central

Qazi, Q H; Kassner, E G; Ganapathy, C

1977-01-01

Since the initial report by Silver et al (1953), more than 50 examples of the Russell-Silver syndrome have been reported. Unilateral congenital asymmetry of the extremities has been considered one of the major features of this disorder (Silver, 1964). We recently observed a child with otherwise typical features of the Russell-Silver syndrome who had enlargement of the right hand and of the left lower extremity. We know of no other recorded example of crossed asymmetry in this clinical entity. Images PMID:839508

Symmetry and asymmetry in aesthetics and the arts

NASA Astrophysics Data System (ADS)

McManus, I. C.

2005-10-01

Symmetry and beauty are often claimed to be linked, particularly by mathematicians and scientists. However philosophers and art historians seem generally agreed that although symmetry is indeed attractive, there is also a somewhat sterile rigidity about it, which can make it less attractive than the more dynamic, less predictable beauty associated with asymmetry. Although a little asymmetry can be beautiful, an excess merely results in chaos. As Adorno suggested, asymmetry probably results most effectively in beauty when the underlying symmetry upon which it is built is still apparent. This paper examines the ways in which asymmetries, particularly left-right asymmetries, were used by painters in the Italian Renaissance. Polyptychs often show occasional asymmetries, which are more likely to involve the substitution of a left cheek for a right cheek, than vice-versa. A hypothesis is developed that the left and right cheeks have symbolic meanings, with the right cheek meaning "like self" and the left cheek meaning "unlike self". This principle is evaluated in pictures such as the Crucifixion, the Annunciation and, the Madonna and Child. The latter is particularly useful because the theological status of the Madonna changed during the Renaissance, and her left-right portrayal also changed at the same time in a comprehensible way. Some brief experimental tests of the hypothesis are also described. Finally the paper ends by considering why it is that the left rather than the right cheek is associated with "unlike self", and puts that result in the context of the universal "dual symbolic classification" of right and left, which was first described by the anthropologist Robert Hertz.

Relative Spatial Frequency Processing Drives Hemispheric Asymmetry in Conscious Awareness

PubMed Central

Piazza, Elise A.; Silver, Michael A.

2017-01-01

Visual stimuli with different spatial frequencies (SFs) are processed asymmetrically in the two cerebral hemispheres. Specifically, low SFs are processed relatively more efficiently in the right hemisphere than the left hemisphere, whereas high SFs show the opposite pattern. In this study, we ask whether these differences between the two hemispheres reflect a low-level division that is based on absolute SF values or a flexible comparison of the SFs in the visual environment at any given time. In a recent study, we showed that conscious awareness of SF information (i.e., visual perceptual selection from multiple SFs simultaneously present in the environment) differs between the two hemispheres. Building upon that result, here we employed binocular rivalry to test whether this hemispheric asymmetry is due to absolute or relative SF processing. In each trial, participants viewed a pair of rivalrous orthogonal gratings of different SFs, presented either to the left or right of central fixation, and continuously reported which grating they perceived. We found that the hemispheric asymmetry in perception is significantly influenced by relative processing of the SFs of the simultaneously presented stimuli. For example, when a medium SF grating and a higher SF grating were presented as a rivalry pair, subjects were more likely to report that they initially perceived the medium SF grating when the rivalry pair was presented in the left visual hemifield (right hemisphere), compared to the right hemifield. However, this same medium SF grating, when it was paired in rivalry with a lower SF grating, was more likely to be perceptually selected when it was in the right visual hemifield (left hemisphere). Thus, the visual system’s classification of a given SF as “low” or “high” (and therefore, which hemisphere preferentially processes that SF) depends on the other SFs that are present, demonstrating that relative SF processing contributes to hemispheric differences in

Cerebral Atrophy

MedlinePlus

... Alzheimer’s disease, Pick’s disease, and fronto-temporal dementia cerebral palsy , in which lesions (damaged areas) may impair motor ... Alzheimer’s disease, Pick’s disease, and fronto-temporal dementia cerebral palsy , in which lesions (damaged areas) may impair motor ...

Comparison of Cerebral Oximeter and Pulse Oximeter Values in the First 72 Hours in Premature, Asphyctic and Healthy Newborns

PubMed Central

Kaya, A; Okur, M; Sal, E; Peker, E; Köstü, M; Tuncer, O; Kirimi, E

2014-01-01

ABSTRACT Aim: The monitoring of oxygenation is essential for providing patient safety and optimal results. We aimed to determine brain oxygen saturation values in healthy, asphyctic and premature newborns and to compare cerebral oximeter and pulse oximeter values in the first 72 hours of life in neonatal intensive care units. Methods: This study was conducted at the neonatal intensive care unit (NICU) of Van Yüzüncü Yil University Research and Administration Hospital. Seventy-five neonatal infants were included in the study (28 asphyxia, 24 premature and 23 mature healthy infants for control group). All infants were studied within the first 72 hours of life. We used a Somanetics 5100C cerebral oximeter (INVOS cerebral/somatic oximeter, Troy, MI, USA). The oxygen saturation information was collected by a Nellcor N-560 pulse oximeter (Nellcor-Puriton Bennet Inc, Pleasanton, CA, USA). Results: In the asphyxia group, the cerebral oximeter average was 76.85 ± 14.1, the pulse oximeter average was 91.86 ± 5.9 and the heart rate average was 139.91 ± 22.3. Among the premature group, the cerebral oximeter average was 79.08 ± 9.04, the pulse oximeter average was 92.01 ± 5.3 and the heart rate average was 135.35 ± 17.03. In the control group, the cerebral oximeter average was 77.56 ± 7.6, the pulse oximeter average was 92.82 ± 3.8 and the heart rate average was 127.04 ± 19.7. Conclusion: Cerebral oximeter is a promising modality in bedside monitoring in neonatal intensive care units. It is complementary to pulse oximeter. It may be used routinely in neonatal intensive care units. PMID:25867556

Baryogenesis and dark matter through a Higgs asymmetry.

PubMed

Servant, Géraldine; Tulin, Sean

2013-10-11

In addition to explaining the masses of elementary particles, the Higgs boson may have far-reaching implications for the generation of the matter content in the Universe. For instance, the Higgs boson plays a key role in two main theories of baryogenesis, namely, electroweak baryogenesis and leptogenesis. In this Letter, we propose a new cosmological scenario where the Higgs chemical potential mediates asymmetries between visible and dark matter sectors, either generating a baryon asymmetry from a dark matter asymmetry or vice versa. We illustrate this mechanism with a simple model with two new fermions coupled to the Higgs boson and discuss the associated signatures.

Decision making in noisy bistable systems with time-dependent asymmetry

NASA Astrophysics Data System (ADS)

Nené, Nuno R.; Zaikin, Alexey

2013-01-01

Our work draws special attention to the importance of the effects of time-dependent parameters on decision making in bistable systems. Here, we extend previous studies of the mechanism known as speed-dependent cellular decision making in genetic circuits by performing an analytical treatment of the canonical supercritical pitchfork bifurcation problem with an additional time-dependent asymmetry and control parameter. This model has an analogous behavior to the genetic switch. In the presence of transient asymmetries and fluctuations, slow passage through the critical region in both systems increases substantially the probability of specific decision outcomes. We also study the relevance for attractor selection of reaching maximum values for the external asymmetry before and after the critical region. Overall, maximum asymmetries should be reached at an instant where the position of the critical point allows for compensation of the detrimental effects of noise in retaining memory of the transient asymmetries.

Cerebral and non-cerebral coenurosis: on the genotypic and phenotypic diversity of Taenia multiceps.

PubMed

Christodoulopoulos, Georgios; Dinkel, Anke; Romig, Thomas; Ebi, Dennis; Mackenstedt, Ute; Loos-Frank, Brigitte

2016-12-01

We characterised the causative agents of cerebral and non-cerebral coenurosis in livestock by determining the mitochondrial genotypes and morphological phenotypes of 52 Taenia multiceps isolates from a wide geographical range in Europe, Africa, and western Asia. Three studies were conducted: (1) a morphological comparison of the rostellar hooks of cerebral and non-cerebral cysts of sheep and goats, (2) a morphological comparison of adult worms experimentally produced in dogs, and (3) a molecular analysis of three partial mitochondrial genes (nad1, cox1, and 12S rRNA) of the same isolates. No significant morphological or genetic differences were associated with the species of the intermediate host. Adult parasites originating from cerebral and non-cerebral cysts differed morphologically, e.g. the shape of the small hooks and the distribution of the testes in the mature proglottids. The phylogenetic analysis of the mitochondrial haplotypes produced three distinct clusters: one cluster including both cerebral isolates from Greece and non-cerebral isolates from tropical and subtropical countries, and two clusters including cerebral isolates from Greece. The majority of the non-cerebral specimens clustered together but did not form a monophyletic group. No monophyletic groups were observed based on geography, although specimens from the same region tended to cluster. The clustering indicates high intraspecific diversity. The phylogenetic analysis suggests that all variants of T. multiceps can cause cerebral coenurosis in sheep (which may be the ancestral phenotype), and some variants, predominantly from one genetic cluster, acquired the additional capacity to produce non-cerebral forms in goats and more rarely in sheep.

Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

ERIC Educational Resources Information Center

National Information Center for Children and Youth with Disabilities, Washington, DC.

This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

Hemispheric Asymmetry in the Efficiency of Attentional Networks

ERIC Educational Resources Information Center

Asanowicz, Dariusz; Marzecova, Anna; Jaskowski, Piotr; Wolski, Piotr

2012-01-01

Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention.…

Magnetic fields and chiral asymmetry in the early hot universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sydorenko, Maksym; Shtanov, Yuri; Tomalak, Oleksandr, E-mail: maxsydorenko@gmail.com, E-mail: tomalak@uni-mainz.de, E-mail: shtanov@bitp.kiev.ua

In this paper, we study analytically the process of external generation and subsequent free evolution of the lepton chiral asymmetry and helical magnetic fields in the early hot universe. This process is known to be affected by the Abelian anomaly of the electroweak gauge interactions. As a consequence, chiral asymmetry in the fermion distribution generates magnetic fields of non-zero helicity, and vice versa. We take into account the presence of thermal bath, which serves as a seed for the development of instability in magnetic field in the presence of externally generated lepton chiral asymmetry. The developed helical magnetic field andmore » lepton chiral asymmetry support each other, considerably prolonging their mutual existence, in the process of 'inverse cascade' transferring magnetic-field power from small to large spatial scales. For cosmologically interesting initial conditions, the chiral asymmetry and the energy density of helical magnetic field are shown to evolve by scaling laws, effectively depending on a single combined variable. In this case, the late-time asymptotics of the conformal chiral chemical potential reproduces the universal scaling law previously found in the literature for the system under consideration. This regime is terminated at lower temperatures because of scattering of electrons with chirality change, which exponentially washes out chiral asymmetry. We derive an expression for the termination temperature as a function of the chiral asymmetry and energy density of helical magnetic field.« less

Significance of postshunt ventricular asymmetries.

PubMed

Linder, M; Diehl, J T; Sklar, F H

1981-08-01

Ventricular asymmetries after shunt surgery were studied. Right and left ventricular areas from pre-and postoperative computerized tomography scans were measured with a computer digitizing technique, and the respective areas were expressed as a ratio. Measurements were made from the scans of 15 hydrocephalic children selected at random. Ages at surgery ranged from 1 to 101 weeks. The results indicate a significantly greater decrease in ventricular size on the side of the ventricular shunt catheter. Multiple regression analysis showed no relationship between the magnitude of change in ventricular size and either the patients' age orn the time intervals between surgery and follow-up scans. Possible mechanisms for these postshunt ventricular asymmetries are discussed.

Ocular adnexal asymmetry in models: a magazine photograph analysis.

PubMed

Ing, Edsel; Safarpour, Azien; Ing, Tom; Ing, Sabrina

2006-04-01

Symmetry of facial features often correlates with a perception of physical attractiveness, and ophthalmologists are sometimes consulted by patients for eyelid, eyebrow, or orbital asymmetry. Our objective was to determine the prevalence of ocular adnexal asymmetry among people generally regarded as attractive. The mean width of the horizontal palpebral fissure (MHPF) for both men and women was determined in 40 adult volunteers. Then unobscured, head-on photographs of models looking in the primary position were digitally scanned from popular magazines. Eyelid height, eyelid folds, eyebrow height, medial canthus to midline distance, pupil to midline distance, and orbital dystopia measurements were made. After the measurements from the models were scaled to size by factoring with the MHPF obtained from the volunteers, the results were analyzed by paired samples t test for right-left asymmetry of the ocular adnexal measurements. We also examined for antimongoloid slant in the models. The MHPF of the volunteers was 27+/-1.3 mm for women and 29.6+/-2.0 mm for men. Of 102 magazine photographs analyzed, 55 were women and 47 men. As a group, the models showed a statistically significant asymmetry (p<0.05) in the horizontal fissure width, upper central lid fold, upper temporal lid fold, central eyebrow height, temporal eyebrow height, medial canthal to midline distance, pupil to midline distance, and orbital dystopia. The female models had more eyebrow asymmetry. The male models had more asymmetry at the horizontal fissure and with orbital dystopia. Two male models also had a unilateral antimongoloid slant. Small to moderate amounts of eyelid, eyebrow, and orbital asymmetry were observed in faces generally perceived as attractive. This fact should be considered during preoperative discussions with patients considering oculoplastic surgery.

Survey of the clinical assessment and utility of near-infrared cerebral oximetry in cardiac surgery.

PubMed

Zacharias, David G; Lilly, Kevin; Shaw, Cynthia L; Pirundini, Paul; Rizzo, Robert J; Body, Simon C; Longford, Nicholas T

2014-04-01

during cardiopulmonary bypass. Scenarios having greatest rScO2 reduction or asymmetry in rScO2 were associated with the highest dispersion, indicating least agreement in management. Scenarios with mild or moderate rScO2 reduction were associated with the lowest dispersion, indicating greater agreement in management. Although experimental data gradually are accumulating to support the role for cerebral oximetry monitoring during cardiac surgery, the results of the present survey support the view that its role remains poorly defined, and consensus for its appropriate use is lacking. Importantly, the authors observed marked variation in the use, perceived utility, and management of patients for 4 of the 6 CPB scenarios between perfusionists and anesthesiologists who share the management of CPB. These findings support the need for well-designed, adequately-powered clinical trials examining the value of this technology. Copyright © 2014 Elsevier Inc. All rights reserved.

The intricate Galaxy disk: velocity asymmetries in Gaia-TGAS

NASA Astrophysics Data System (ADS)

Antoja, T.; de Bruijne, J.; Figueras, F.; Mor, R.; Prusti, T.; Roca-Fàbrega, S.

2017-06-01

We use Gaia-TGAS data to compare the transverse velocities in Galactic longitude (coming from proper motions and parallaxes) in the Milky Way disk for negative and positive longitudes as a function of distance. The transverse velocities are strongly asymmetric and deviate significantly from the expectations for an axisymmetric galaxy. The value and sign of the asymmetry changes at spatial scales of several tens of degrees in Galactic longitude and about 0.5 kpc in distance. The asymmetry is statistically significant at 95% confidence level for 57% of the region probed, which extends up to 1.2 kpc. A percentage of 24% of the region shows absolute differences at this confidence level larger than 5 km s-1 and 7% larger than 10 km s-1. The asymmetry pattern shows mild variations in the vertical direction and with stellar type. A first qualitative comparison with spiral arm models indicates that the arms are probably not the main source of the asymmetry. We briefly discuss alternative origins. This is the first time that global all-sky asymmetries are detected in the Milky Way kinematics beyond the local neighbourhood and with a purely astrometric sample.

Co-clustering directed graphs to discover asymmetries and directional communities

PubMed Central

Rohe, Karl; Qin, Tai; Yu, Bin

2016-01-01

In directed graphs, relationships are asymmetric and these asymmetries contain essential structural information about the graph. Directed relationships lead to a new type of clustering that is not feasible in undirected graphs. We propose a spectral co-clustering algorithm called di-sim for asymmetry discovery and directional clustering. A Stochastic co-Blockmodel is introduced to show favorable properties of di-sim. To account for the sparse and highly heterogeneous nature of directed networks, di-sim uses the regularized graph Laplacian and projects the rows of the eigenvector matrix onto the sphere. A nodewise asymmetry score and di-sim are used to analyze the clustering asymmetries in the networks of Enron emails, political blogs, and the Caenorhabditis elegans chemical connectome. In each example, a subset of nodes have clustering asymmetries; these nodes send edges to one cluster, but receive edges from another cluster. Such nodes yield insightful information (e.g., communication bottlenecks) about directed networks, but are missed if the analysis ignores edge direction. PMID:27791058

Co-clustering directed graphs to discover asymmetries and directional communities.

PubMed

Rohe, Karl; Qin, Tai; Yu, Bin

2016-10-21

In directed graphs, relationships are asymmetric and these asymmetries contain essential structural information about the graph. Directed relationships lead to a new type of clustering that is not feasible in undirected graphs. We propose a spectral co-clustering algorithm called di-sim for asymmetry discovery and directional clustering. A Stochastic co-Blockmodel is introduced to show favorable properties of di-sim To account for the sparse and highly heterogeneous nature of directed networks, di-sim uses the regularized graph Laplacian and projects the rows of the eigenvector matrix onto the sphere. A nodewise asymmetry score and di-sim are used to analyze the clustering asymmetries in the networks of Enron emails, political blogs, and the Caenorhabditis elegans chemical connectome. In each example, a subset of nodes have clustering asymmetries; these nodes send edges to one cluster, but receive edges from another cluster. Such nodes yield insightful information (e.g., communication bottlenecks) about directed networks, but are missed if the analysis ignores edge direction.

Communication Apprehension and Resting Alpha Range Asymmetry in the Anterior Cortex

ERIC Educational Resources Information Center

Beatty, Michael J.; Heisel, Alan D.; Lewis, Robert J.; Pence, Michelle E.; Reinhart, Amber; Tian, Yan

2011-01-01

In this study, we examined the relationship between trait-like communication apprehension (CA) and resting alpha range asymmetry in the anterior cortex (AC). Although theory and research in cognitive neuroscience suggest that asymmetry in the AC constitutes a relatively stable, inborn, substrate of emotion, some studies indicate that asymmetry can…

Challenging Postural Tasks Increase Asymmetry in Patients with Parkinson’s Disease

PubMed Central

Beretta, Victor Spiandor; Gobbi, Lilian Teresa Bucken; Lirani-Silva, Ellen; Simieli, Lucas; Orcioli-Silva, Diego; Barbieri, Fabio Augusto

2015-01-01

The unilateral predominance of Parkinson’s disease (PD) symptoms suggests that balance control could be asymmetrical during static tasks. Although studies have shown that balance control asymmetries exist in patients with PD, these analyses were performed using only simple bipedal standing tasks. Challenging postural tasks, such as unipedal or tandem standing, could exacerbate balance control asymmetries. To address this, we studied the impact of challenging standing tasks on postural control asymmetry in patients with PD. Twenty patients with PD and twenty neurologically healthy individuals (control group) participated in this study. Participants performed three 30s trials for each postural task: bipedal, tandem adapted and unipedal standing. The center of pressure parameter was calculated for both limbs in each of these conditions, and the asymmetry between limbs was assessed using the symmetric index. A significant effect of condition was observed, with unipedal standing and tandem standing showing greater asymmetry than bipedal standing for the mediolateral root mean square (RMS) and area of sway parameters, respectively. In addition, a group*condition interaction indicated that, only for patients with PD, the unipedal condition showed greater asymmetry in the mediolateral RMS and area of sway than the bipedal condition and the tandem condition showed greater asymmetry in the area of sway than the bipedal condition. Patients with PD exhibited greater asymmetry while performing tasks requiring postural control when compared to neurologically healthy individuals, especially for challenging tasks such as tandem and unipedal standing. PMID:26367032

Frontal alpha asymmetry and sexually motivated states.

PubMed

Prause, Nicole; Staley, Cameron; Roberts, Verena

2014-03-01

Anterior alpha asymmetry of electroencephalographic (EEG) signals has been suggested to index state approach (or avoidance) motivation. This model has not yet been extended to high approach-motivation sexual stimuli, which may represent an important model of reward system function. Sixty-five participants viewed a neutral and a sexually motivating film while their EEG was recorded, and reported their sexual feelings after each film. Greater alpha power in the left hemisphere during sexually motivated states was evident. A positive relationship between self-reported mental sexual arousal and alpha asymmetry was identified, where coherence between these indicators was higher in women. Notably, coherence was stronger when mental versus physical sexual arousal was rated. Alpha asymmetry appears to offer a new method for further examining this novel coherence pattern across men and women. Copyright © 2014 Society for Psychophysiological Research.

Hemispheric asymmetry in the efficiency of attentional networks.

PubMed

Asanowicz, Dariusz; Marzecová, Anna; Jaśkowski, Piotr; Wolski, Piotr

2012-07-01

Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention. Participants (N=125) were tested with the Lateralized Attention Network Test (LANT) that allowed us to investigate the efficiency of the networks in both visual fields (VF). We found a LVF advantage when a target occurred in an unattended location, which seems to reflect right hemisphere superiority in control of the reorienting of attention. Furthermore, a LVF advantage in conflict resolution was observed, which may indicate hemispheric asymmetry of the executive network. No VF effect for alerting was found. The results, consistent with the common notion of general right hemisphere dominance for attention, provide a more detailed account of hemispheric asymmetries of the attentional networks than previous studies using the LANT task. Copyright © 2012 Elsevier Inc. All rights reserved.

Search asymmetries: parallel processing of uncertain sensory information.

PubMed

Vincent, Benjamin T

2011-08-01

What is the mechanism underlying search phenomena such as search asymmetry? Two-stage models such as Feature Integration Theory and Guided Search propose parallel pre-attentive processing followed by serial post-attentive processing. They claim search asymmetry effects are indicative of finding pairs of features, one processed in parallel, the other in serial. An alternative proposal is that a 1-stage parallel process is responsible, and search asymmetries occur when one stimulus has greater internal uncertainty associated with it than another. While the latter account is simpler, only a few studies have set out to empirically test its quantitative predictions, and many researchers still subscribe to the 2-stage account. This paper examines three separate parallel models (Bayesian optimal observer, max rule, and a heuristic decision rule). All three parallel models can account for search asymmetry effects and I conclude that either people can optimally utilise the uncertain sensory data available to them, or are able to select heuristic decision rules which approximate optimal performance. Copyright © 2011 Elsevier Ltd. All rights reserved.

Critical asymmetry in renormalization group theory for fluids.

PubMed

Zhao, Wei; Wu, Liang; Wang, Long; Li, Liyan; Cai, Jun

2013-06-21

The renormalization-group (RG) approaches for fluids are employed to investigate critical asymmetry of vapour-liquid equilibrium (VLE) of fluids. Three different approaches based on RG theory for fluids are reviewed and compared. RG approaches are applied to various fluid systems: hard-core square-well fluids of variable ranges, hard-core Yukawa fluids, and square-well dimer fluids and modelling VLE of n-alkane molecules. Phase diagrams of simple model fluids and alkanes described by RG approaches are analyzed to assess the capability of describing the VLE critical asymmetry which is suggested in complete scaling theory. Results of thermodynamic properties obtained by RG theory for fluids agree with the simulation and experimental data. Coexistence diameters, which are smaller than the critical densities, are found in the RG descriptions of critical asymmetries of several fluids. Our calculation and analysis show that the approach coupling local free energy with White's RG iteration which aims to incorporate density fluctuations into free energy is not adequate for VLE critical asymmetry due to the inadequate order parameter and the local free energy functional used in the partition function.

Creation and Evolution of Particle Number Asymmetry in an Expanding Universe

NASA Astrophysics Data System (ADS)

Morozumi, T.; Nagao, K. I.; Adam, A. S.; Takata, H.

2017-03-01

We introduce a model which may generate particle number asymmetry in an expanding Universe. The model includes charge parity (CP) violating and particle number violating interactions. The model consists of a real scalar field and a complex scalar field. Starting with an initial condition specified by a density matrix, we show how the asymmetry is created through the interaction and how it evolves at later time. We compute the asymmetry using non-equilibrium quantum field theory and as a first test of the model, we study how the asymmetry evolves in the flat limit.

Complementary and Alternative Therapies

PubMed Central

Moore, Mary Lou

2002-01-01

Complementary and alternative therapies are increasingly used by many pregnant women in the United States; however, limited research is available on many therapies. The number of studies should increase with the establishment of the National Center for Complementary and Alternative Medicine by the National Institutes of Health. This column reviews recent studies of both herbal medicines and alternative therapies used in pregnancy. PMID:17273285

Line asymmetry in the Seyfert Galaxy NGC 3783

NASA Technical Reports Server (NTRS)

Ramirez, J. M.; Bautista, Manuel; Kallman, Timothy

2005-01-01

We have reanalyzed the 900 ks Chandra X-ray spectrum of NGC 3783, finding evidence on the asymmetry of the spectral absorption lines. The lines are fitted with a parametric expression that results from an analytical treatment of radiatively driven winds. The line asymmetry distribution derived from the spectrum is consistent with a non-spherical outflow with a finite optical depth. Within this scenario, our model explains the observed correlations between the line velocity shifts and the ionization parameter and between the line velocity shift and the line asymmetry. The present results may provide a framework for detailed testing of models for the dynamic and physical properties of warm absorber in Seyfert galaxies.

Yield Asymmetry Design of Magnesium Alloys by Integrated Computational Materials Engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dongsheng; Joshi, Vineet V.; Lavender, Curt A.

2013-11-01

Deformation asymmetry of magnesium alloys is an important factor on machine design in automobile industry. Represented by the ratio of compressive yield stress (CYS) against tensile yield stress (TYS), deformation asymmetry is strongly related to microstructure, characterized by texture and grain size. Modified intermediate phi-model, a polycrystalline viscoplasticity model, is used to predict the deformation behavior of magnesium alloys with different grain sizes. Validated with experimental results, integrated computational materials engineering is applied to find out the route in achieving desired asymmetry by thermomechanical processing. In some texture, for example, rolled texture, CYS/TYS is smaller than 1 under different loadingmore » directions. In some texture, for example, extruded texture, asymmetry is large along normal direction. Starting from rolled texture, the asymmetry will increased to close to 1 along rolling direction after compressed to a strain of 0.2. Our model shows that grain refinement increases CYS/TYS. Besides texture control, grain refinement can also optimize the yield asymmetry. After the grain size decreased to a critical value, CYS/TYS reaches to 1 since CYS increases much faster than TYS. By tailoring the microstructure using texture control and grain refinement, it is achievable to optimize yield asymmetry in wrought magnesium alloys.« less

Hyperventilation, cerebral perfusion, and syncope.

PubMed

Immink, R V; Pott, F C; Secher, N H; van Lieshout, J J

2014-04-01

This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2 the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established.

Targeted presurgical decompensation in patients with yaw-dependent facial asymmetry

PubMed Central

Kim, Kyung-A; Lee, Ji-Won; Park, Jeong-Ho; Kim, Byoung-Ho; Ahn, Hyo-Won

2017-01-01

Facial asymmetry can be classified into the rolling-dominant type (R-type), translation-dominant type (T-type), yawing-dominant type (Y-type), and atypical type (A-type) based on the distorted skeletal components that cause canting, translation, and yawing of the maxilla and/or mandible. Each facial asymmetry type represents dentoalveolar compensations in three dimensions that correspond to the main skeletal discrepancies. To obtain sufficient surgical correction, it is necessary to analyze the main skeletal discrepancies contributing to the facial asymmetry and then the skeletal-dental relationships in the maxilla and mandible separately. Particularly in cases of facial asymmetry accompanied by mandibular yawing, it is not simple to establish pre-surgical goals of tooth movement since chin deviation and posterior gonial prominence can be either aggravated or compromised according to the direction of mandibular yawing. Thus, strategic dentoalveolar decompensations targeting the real basal skeletal discrepancies should be performed during presurgical orthodontic treatment to allow for sufficient skeletal correction with stability. In this report, we document targeted decompensation of two asymmetry patients focusing on more complicated yaw-dependent types than others: Y-type and A-type. This may suggest a clinical guideline on the targeted decompensation in patient with different types of facial asymmetries. PMID:28523246

Targeted presurgical decompensation in patients with yaw-dependent facial asymmetry.

PubMed

Kim, Kyung-A; Lee, Ji-Won; Park, Jeong-Ho; Kim, Byoung-Ho; Ahn, Hyo-Won; Kim, Su-Jung

2017-05-01

Facial asymmetry can be classified into the rolling-dominant type (R-type), translation-dominant type (T-type), yawing-dominant type (Y-type), and atypical type (A-type) based on the distorted skeletal components that cause canting, translation, and yawing of the maxilla and/or mandible. Each facial asymmetry type represents dentoalveolar compensations in three dimensions that correspond to the main skeletal discrepancies. To obtain sufficient surgical correction, it is necessary to analyze the main skeletal discrepancies contributing to the facial asymmetry and then the skeletal-dental relationships in the maxilla and mandible separately. Particularly in cases of facial asymmetry accompanied by mandibular yawing, it is not simple to establish pre-surgical goals of tooth movement since chin deviation and posterior gonial prominence can be either aggravated or compromised according to the direction of mandibular yawing. Thus, strategic dentoalveolar decompensations targeting the real basal skeletal discrepancies should be performed during presurgical orthodontic treatment to allow for sufficient skeletal correction with stability. In this report, we document targeted decompensation of two asymmetry patients focusing on more complicated yaw-dependent types than others: Y-type and A-type. This may suggest a clinical guideline on the targeted decompensation in patient with different types of facial asymmetries.

Effects of Convective Asymmetries on Hurricane Intensity: A Numerical Study

NASA Technical Reports Server (NTRS)

Wu, Liguang; Braun, Scott A.

2003-01-01

The influence of the uniform large-scale flow, beta effect, and vertical shear of the environmental flow on hurricane intensity is investigated in the context of the induced convective or potential vorticity asymmetries with a hydrostatic primitive equation hurricane model. In agreement with the previous studies, imposing of one of these environmental effects can substantially weaken the simulated tropical cyclones. In response t o the environmental influence, significant asymmetries develop with a structure similar to the spiral bands in real hurricanes, which are dominated by wavenumber-one components. The tendencies of the mean radial, azimuthal winds and temperature associated with the environment-induced convective asymmetries are evaluated respectively. The resulting asymmetries can effectively reduce hurricane intensity by directly producing the negative tendency of the mean tangential wind in the vicinity of the radius of maximum wind, and by weakening the mean radial circulation. The reduction effects are closely associated with the spiral structure of the induced asymmetries. The time lag observed between the imposition of the environmental influence and the resulting rise in the minimum central pressure is the time required for developing the spiral structure. This study also confirms the axisymmetrization process associated with the induced wavenumber-one components of potential vorticity asymmetries, but it exists only within the radius of maximum wind.

Complementary approaches to palliative oncological care.

PubMed

Zappa, Simone B; Cassileth, Barrie R

2003-01-01

The popularity of complementary and alternative medicine (CAM) has increased tremendously in recent years. Thus, it is imperative to distinguish between alternative therapies that can be dangerous and complementary therapies that are primarily palliative and augment conventional treatment. Memorial Sloan-Kettering Cancer Center's Integrative Medicine Service offers complementary therapies to patients in an attempt to improve quality of life and provide symptom management. In addition to clinical services, it also provides education to health care professionals and the public and performs clinical and laboratory research on complementary modalities and the antitumor properties of botanicals. If CAM is to be accepted by mainstream medicine, research must be done usingstandard research methodologies.

Oral contraceptive therapy modulates hemispheric asymmetry in spatial attention.

PubMed

Cicinelli, Ettore; De Tommaso, Marina; Cianci, Antonio; Colacurci, Nicola; Rella, Leonarda; Loiudice, Luisa; Cicinelli, Maria Vittoria; Livrea, Paolo

2011-12-01

Functional cerebral asymmetries (FCAs) are known to fluctuate across the menstrual cycle. The visual line-bisection task administered to normally cycling women showed different patterns of the interhemispheric interactions during menses and the midluteal cycle phase. However, the contribution of estrogens and progestins hormones to this phenomenon is still unclear. The aim of our study was to show a variation of FCAs in women administered oral contraceptives (OCs) using the visual line-bisection task. Visual line-bisection task with three horizontal lines was administered to 36 healthy women taking a 21-day OC. Twenty-nine patients were right handed. The task was administered during OC intake (day 10) and at the end of the pill-free period. The right-handed women showed a significant leftward bias of veridical center on the first and third lines during OC intake compared with an opposite rightward bias during the pill-free period. The same phenomenon of contralateral deviation was observed in left-handed women on day 10 of OC intake. The results of this study confirm a hormonal modulation on interhemispheric interaction and suggest that OCs may improve the interhemispheric interaction reducing FCAs compared with the low hormone level period. This opens new insights in OC prescription and choice of administration schedule in order to improve cognitive performances. Copyright © 2011 Elsevier Inc. All rights reserved.

Substrate Stiffness Regulates the Development of Left-Right Asymmetry in Cell Orientation.

PubMed

Bao, Yuanye; Huang, Yaozhun; Lam, Miu Ling; Xu, Ting; Zhu, Ninghao; Guo, Zhaobin; Cui, Xin; Lam, Raymond H W; Chen, Ting-Hsuan

2016-07-20

Left-right (LR) asymmetry of tissue/organ structure is a morphological feature essential for many tissue functions. The ability to incorporate the LR formation in constructing tissue/organ replacement is important for recapturing the inherent tissue structure and functions. However, how LR asymmetry is formed remains largely underdetermined, which creates significant hurdles to reproduce and regulate the formation of LR asymmetry in an engineering context. Here, we report substrate rigidity functioning as an effective switch that turns on the development of LR asymmetry. Using micropatterned cell-adherent stripes on rigid substrates, we found that cells collectively oriented at a LR-biased angle relative to the stripe boundary. This LR asymmetry was initiated by a LR-biased migration of cells at stripe boundary, which later generated a velocity gradient propagating from stripe boundary to the center. After a series of cell translocations and rotations, ultimately, an LR-biased cell orientation within the micropatterned stripe was formed. Importantly, this initiation and propagation of LR asymmetry was observed only on rigid but not on soft substrates, suggesting that the LR asymmetry was regulated by rigid substrate probably through the organization of actin cytoskeleton. Together, we demonstrated substrate rigidity as a determinant factor that mediates the self-organizing LR asymmetry being unfolded from single cells to multicellular organization. More broadly, we anticipate that our findings would pave the way for rebuilding artificial tissue constructs with inherent LR asymmetry in the future.

Mandibular asymmetry and the fourth dimension.

PubMed

Kaban, Leonard B

2009-03-01

This paper represents more than 30 years of discussion and collaboration with Drs Joseph Murray and John Mulliken in an attempt to understand growth patterns over time (ie, fourth dimension) in patients with hemifacial microsomia (HFM). This is essential for the development of rational treatment protocols for children and adults with jaw asymmetry. Traditionally, HFM was thought of as a unilateral deformity, but it was recognized that 20% to 30% of patients had bilateral abnormalities. However, early descriptions of skeletal correction addressed almost exclusively lengthening of the short (affected) side of the face. Based on longitudinal clinical observations of unoperated HFM patients, we hypothesized that abnormal mandibular growth is the earliest skeletal manifestation and that restricted growth of the mandible plays a pivotal role in progressive distortion of both the ipsilateral and contralateral facial skeleton. This hypothesis explains the progressive nature of the asymmetry in patients with HFM and provides the rationale for surgical lengthening of the mandible in children to prevent end-stage deformity. During the past 30 years, we have learned that this phenomenon of progressive distortion of the adjacent and contralateral facial skeleton occurs with other asymmetric mandibular undergrowth (tumor resection, radiation therapy, or posttraumatic defects) and overgrowth (mandibular condylar hyperplasia) conditions. In this paper, I describe the progression of deformity with time in patients with mandibular asymmetry as a result of undergrowth and overgrowth. Understanding these concepts is critical for the development of rational treatment protocols for adults with end-stage asymmetry and for children to minimize secondary deformity.

An Evidence-Based Course in Complementary Medicines

PubMed Central

Hughes, Jeff

2012-01-01

Objective. To evaluate the impact of an evidence-based course in complementary medicines on the attitudes, knowledge, and professional practice behavior of undergraduate pharmacy students. Design. A required 12-week evidence-based complementary medicine course was designed and introduced into the third-year undergraduate pharmacy curriculum. The course included a combination of traditional lectures, interactive tutorial sessions, and a range of formal assessments. Assessment. Pre- and post-course survey instruments were administered to assess changes in students’ attitudes, perceptions, knowledge, and the likelihood they would recommend the use of complementary medicines in a pharmacy practice environment. Conclusion. Completion of a required evidence-based complementary medicines course resulted in a positive change in pharmacy students’ perceptions of the value of various complementary medicines as well as in their willingness to recommend them, and provided students with the required knowledge to make patient-centered recommendations for use of complementary medicines in a professional pharmacy practice setting. These findings support the need for greater evidence-based complementary medicine education within pharmacy curricula to meet consumer demand and to align with pharmacists’ professional responsibilities. PMID:23275665

Left-right asymmetries and shape analysis on Ceroglossus chilensis (Coleoptera: Carabidae)

NASA Astrophysics Data System (ADS)

Bravi, Raffaella; Benítez, Hugo A.

2013-10-01

Bilateral symmetry is widespread in animal kingdom, however most animal can deviate from expected symmetry and manifest some kind of asymmetries. Fluctuating asymmetry is considered as a tool for valuating developmental instability, whereas directional asymmetry is inherited and could be used for evaluating evolutionary development. We use the method of geometric morphometrics to analyze left/right asymmetries in the whole body, in two sites and totally six populations of Ceroglossus chilensis with the aim to infer and explain morphological disparities between populations and sexes in this species. In all individuals analyzed we found both fluctuating asymmetry and directional asymmetry for size and shape variation components, and a high sexual dimorphism. Moreover a high morphological variability between the two sites emerged as well. Differences in diet could influence the expression of morphological variation and simultaneously affect body sides, and therefore contribute to the symmetric component of variation. Moreover differences emerged between two sites could be a consequence of isolation and fragmentation, rather than a response to local environmental differences between sampling sites.

Prefrontal Asymmetry and Parent-Rated Temperament in Infants

PubMed Central

LoBue, Vanessa; Coan, James A.; Thrasher, Cat; DeLoache, Judy S.

2011-01-01

Indicators of temperament appear early in infancy and remain relatively stable over time. Despite a great deal of interest in biological indices of temperament, most studies of infant temperament rely on parental reports or behavioral tasks. Thus, the extent to which commonly used temperament measures relate to potential biological indicators of infant temperament is still relatively unknown. The current experiment examines the relationship between a common parental report measure of temperament – the Infant Behavior Questionnaire – Revised (IBQ-R) – and measures of frontal EEG asymmetry in infants. We examined associations between the subscales of the IBQ-R and frontal EEG asymmetry scores recorded during a combined series of neutral attentional and putatively emotional recording conditions in infants between 7 and 9 months of age. We predicted that approach-related subscales of the IBQ-R (e.g., Approach, Soothability) would be related to greater left prefrontal asymmetry, while withdrawal-related subscales (e.g., Distress to Limitations, Fear, Falling Reactivity, Perceptual Sensitivity) would be related to greater right prefrontal asymmetry. In the mid- and lateral-frontal regions, Approach, Distress to Limitations, Fear, Soothability, and Perceptual Sensitivity were generally associated with greater left frontal activation (rs≥.23, ps<0.05), while only Falling Reactivity was associated with greater right frontal activation (rs≤−.44, ps<0.05). Results suggest that variability in frontal EEG asymmetry is robustly associated with parental report measures of temperament in infancy. PMID:21829482

Effects of hyperglycemia and effects of ketosis on cerebral perfusion, cerebral water distribution, and cerebral metabolism.

PubMed

Glaser, Nicole; Ngo, Catherine; Anderson, Steven; Yuen, Natalie; Trifu, Alexandra; O'Donnell, Martha

2012-07-01

Diabetic ketoacidosis (DKA) may cause brain injuries in children. The mechanisms responsible are difficult to elucidate because DKA involves multiple metabolic derangements. We aimed to determine the independent effects of hyperglycemia and ketosis on cerebral metabolism, blood flow, and water distribution. We used magnetic resonance spectroscopy to measure ratios of cerebral metabolites (ATP to inorganic phosphate [Pi], phosphocreatine [PCr] to Pi, N-acetyl aspartate [NAA] to creatine [Cr], and lactate to Cr) and diffusion-weighted imaging and perfusion-weighted imaging to assess cerebral water distribution (apparent diffusion coefficient [ADC] values) and cerebral blood flow (CBF) in three groups of juvenile rats (hyperglycemic, ketotic, and normal control). ATP-to-Pi ratio was reduced in both hyperglycemic and ketotic rats in comparison with controls. PCr-to-Pi ratio was reduced in the ketotic group, and there was a trend toward reduction in the hyperglycemic group. No significant differences were observed in NAA-to-Cr or lactate-to-Cr ratio. Cortical ADC was reduced in both groups (indicating brain cell swelling). Cortical CBF was also reduced in both groups. We conclude that both hyperglycemia and ketosis independently cause reductions in cerebral high-energy phosphates, CBF, and cortical ADC values. These effects may play a role in the pathophysiology of DKA-related brain injury.

Left-right asymmetry specification in amphioxus: review and prospects.

PubMed

Soukup, Vladimir

2017-01-01

Extant bilaterally symmetrical animals usually show asymmetry in the arrangement of their inner organs. However, the exaggerated left-right (LR) asymmetry in amphioxus represents a true peculiarity among them. The amphioxus larva shows completely disparate fates of left and right body sides, so that organs associated with pharynx are either positioned exclusively on the left or on the right side. Moreover, segmented paraxial structures such as muscle blocks and their neuronal innervation show offset arrangement between the sides making it difficult to propose any explanation or adaptivity to larval and adult life. First LR asymmetries can be traced back to an early embryonic period when morphological asymmetries are preceded by molecular asymmetries driven by the action of the Nodal signaling pathway. This review sums up recent advances in understanding LR asymmetry specification in amphioxus and proposes upstream events that may regulate asymmetric Nodal signaling. These events include the presence of the vertebrate-like LR organizer and a cilia-driven fluid flow that may be involved in the breaking of bilateral symmetry. The upstream pathways comprising the ion flux, Delta/Notch, Wnt/β-catenin and Wnt/PCP are hypothesized to regulate both formation of the LR organizer and expression of the downstream Nodal signaling pathway genes. These suggestions are in line with what we know from vertebrate and ambulacrarian LR axis specification and are directly testable by experimental manipulations. Thanks to the phylogenetic position of amphioxus, the proposed mechanisms may be helpful in understanding the evolution of LR axis specification across deuterostomes.

New Views on Strand Asymmetry in Insect Mitochondrial Genomes

PubMed Central

Wei, Shu-Jun; Shi, Min; Chen, Xue-Xin; Sharkey, Michael J.; van Achterberg, Cornelis; Ye, Gong-Yin; He, Jun-Hua

2010-01-01

Strand asymmetry in nucleotide composition is a remarkable feature of animal mitochondrial genomes. Understanding the mutation processes that shape strand asymmetry is essential for comprehensive knowledge of genome evolution, demographical population history and accurate phylogenetic inference. Previous studies found that the relative contributions of different substitution types to strand asymmetry are associated with replication alone or both replication and transcription. However, the relative contributions of replication and transcription to strand asymmetry remain unclear. Here we conducted a broad survey of strand asymmetry across 120 insect mitochondrial genomes, with special reference to the correlation between the signs of skew values and replication orientation/gene direction. The results show that the sign of GC skew on entire mitochondrial genomes is reversed in all species of three distantly related families of insects, Philopteridae (Phthiraptera), Aleyrodidae (Hemiptera) and Braconidae (Hymenoptera); the replication-related elements in the A+T-rich regions of these species are inverted, confirming that reversal of strand asymmetry (GC skew) was caused by inversion of replication origin; and finally, the sign of GC skew value is associated with replication orientation but not with gene direction, while that of AT skew value varies with gene direction, replication and codon positions used in analyses. These findings show that deaminations during replication and other mutations contribute more than selection on amino acid sequences to strand compositions of G and C, and that the replication process has a stronger affect on A and T content than does transcription. Our results may contribute to genome-wide studies of replication and transcription mechanisms. PMID:20856815

Perceptual asymmetry in texture perception.

PubMed

Williams, D; Julesz, B

1992-07-15

A fundamental property of human visual perception is our ability to distinguish between textures. A concerted effort has been made to account for texture segregation in terms of linear spatial filter models and their nonlinear extensions. However, for certain texture pairs the ease of discrimination changes when the role of figure and ground are reversed. This asymmetry poses a problem for both linear and nonlinear models. We have isolated a property of texture perception that can account for this asymmetry in discrimination: subjective closure. This property, which is also responsible for visual illusions, appears to be explainable by early visual processes alone. Our results force a reexamination of the process of human texture segregation and of some recent models that were introduced to explain it.

Analysis of Facial Asymmetry in Deformational Plagiocephaly Using Three-Dimensional Computed Tomographic Review

PubMed Central

Moon, Il Yung; Oh, Kap Sung

2014-01-01

Background Infants with deformational plagiocephaly (DP) usually present with cranial vault deformities as well as facial asymmetry. The purpose of this study was to use three-dimensional anthropometric data to evaluate the influence of cranial deformities on facial asymmetry. Methods We analyzed three-dimensional computed tomography data for infants with DP (n=48) and without DP (n=30, control). Using 16 landmarks and 3 reference planes, 22 distance parameters and 2 angular parameters were compared. This cephalometric assessment focused on asymmetry of the orbits, nose, ears, maxilla, and mandible. We then assessed the correlation between 23 of the measurements and cranial vault asymmetry (CVA) for statistical significance using relative differences and correlation analysis. Results With the exception of few orbital asymmetry variables, most measurements indicated that the facial asymmetry was greater in infants with DP. Mandibular and nasal asymmetry was correlated highly with severity of CVA. Shortening of the ipsilateral mandibular body was particularly significant. There was no significant deformity in the maxilla or ear. Conclusion This study demonstrated that the cranial vault deformity in DP is associated with facial asymmetry. Compared with the control group, the infants with DP were found to have prominent asymmetry of the nose and mandible. PMID:28913202

Cerebral palsy - resources

MedlinePlus

Resources - cerebral palsy ... The following organizations are good resources for information on cerebral palsy : National Institute of Neurological Disorders and Stroke -- www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope- ...

Sources of Local Time Asymmetries in Magnetodiscs

NASA Astrophysics Data System (ADS)

Arridge, C. S.; Kane, M.; Sergis, N.; Khurana, K. K.; Jackman, C. M.

2015-04-01

The rapidly rotating magnetospheres at Jupiter and Saturn contain a near-equatorial thin current sheet over most local times known as the magnetodisc, resembling a wrapped-up magnetotail. The Pioneer, Voyager, Ulysses, Galileo, Cassini and New Horizons spacecraft at Jupiter and Saturn have provided extensive datasets from which to observationally identify local time asymmetries in these magnetodiscs. Imaging in the infrared and ultraviolet from ground- and space-based instruments have also revealed the presence of local time asymmetries in the aurora which therefore must map to local time asymmetries in the magnetosphere. Asymmetries are found in (i) the configuration of the magnetic field and magnetospheric currents, where a thicker disc is found in the noon and dusk sectors; (ii) plasma flows where the plasma flow has local time-dependent radial components; (iii) a thicker plasma sheet in the dusk sector. Many of these features are also reproduced in global MHD simulations. Several models have been developed to interpret these various observations and typically fall into two groups: ones which invoke coupling with the solar wind (via reconnection or viscous processes) and ones which invoke internal rotational processes operating inside an asymmetrical external boundary. In this paper we review these observational in situ findings, review the models which seek to explain them, and highlight open questions and directions for future work.

Patterns of directional asymmetry in the pelvis and pelvic canal.

PubMed

Tobolsky, Victoria A; Kurki, Helen K; Stock, Jay T

2016-11-01

The human pelvis is unique among modern taxa for supporting both parturition of large brained young and obligate bipedalism. Though much work has focused on pelvic development and variation, little work has explored the presence or absence of asymmetry in the pelvis despite well-known patterns of asymmetry in other skeletal regions. This study investigated whether patterns of directional asymmetry (DA) could be observed in the pelvis or pelvic canal. Seventeen bilaterally paired osteometric measurements of the os coxae (34 measures in total) were taken from 128 skeletons (female n = 65, male n = 63) from recent human populations in five geographic regions. Paired sample t-tests and Mann-Whitney U-tests were used to investigate DA. Results from a pooled sample of all individuals showed that the pelvis exhibited a left-bias in DA. In contrast, the pelvic canal exhibited a pattern in which the anterior canal exhibited a right-bias and the posterior canal exhibited a left-bias. Neither sex nor populational differences in DA were observed in the pelvis or pelvic canal. The varying patterns of asymmetry uncovered here accord with prior work and may indicate that loading from the trunk and legs place differing stresses on the pelvis and canal, yielding these unequal asymmetries. However, this is speculative and the possible influence of genetics, biomechanics, and nutritional status on the development of pelvic and canal asymmetries presents a rich area for future study. Additionally, the potential influence of pelvic canal asymmetry on obstetric measures of pelvic capacity merits future research. Am. J. Hum. Biol. 28:804-810, 2016. © 2016Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Quantification of upper limb kinetic asymmetries in front crawl swimming.

PubMed

Morouço, Pedro G; Marinho, Daniel A; Fernandes, Ricardo J; Marques, Mário C

2015-04-01

This study aimed at quantifying upper limb kinetic asymmetries in maximal front crawl swimming and to examine if these asymmetries would affect the contribution of force exertion to swimming performance. Eighteen high level male swimmers with unilateral breathing patterns and sprint or middle distance specialists, volunteered as participants. A load-cell was used to quantify the forces exerted in water by completing a 30s maximal front crawl tethered swimming test and a maximal 50 m free swimming was considered as a performance criterion. Individual force-time curves were obtained to calculate the mean and maximum forces per cycle, for each upper limb. Following, symmetry index was estimated and breathing laterality identified by questionnaire. Lastly, the pattern of asymmetries along the test was estimated for each upper limb using linear regression of peak forces per cycle. Asymmetrical force exertion was observed in the majority of the swimmers (66.7%), with a total correspondence of breathing laterality opposite to the side of the force asymmetry. Forces exerted by the dominant upper limb presented a higher decrease than from the non-dominant. Very strong associations were found between exerted forces and swimming performance, when controlling the isolated effect of symmetry index. Results point that force asymmetries occur in the majority of the swimmers, and that these asymmetries are most evident in the first cycles of a maximum bout. Symmetry index stood up as an influencing factor on the contribution of tethered forces over swimming performance. Thus, to some extent, a certain degree of asymmetry is not critical for short swimming performance. Copyright © 2015 Elsevier B.V. All rights reserved.

Auxin Asymmetry during Gravitropism by Tomato Hypocotyls 1

PubMed Central

Harrison, Marcia A.; Pickard, Barbara G.

1989-01-01

Gravitropic asymmetry of auxin was observed in hypocotyls of tomato (Lycopersicon esculentum Mill.) soon after horizontal placement: the ratio of apically supplied [3H]IAA collected from the lower sides to that from the upper sides was about 1.4 between 5 and 10 minutes. This was adequately early to account for the beginning of curvature. The auxin asymmetry ratio rose to about 2.5 between 20 and 25 minutes, and to 3.5 during the main phase of curvature. This compares reasonably well with the roughly 3.9 ratio for elongation on the lower side to elongation on the upper side that is the basis for the curvature. These data extend evidence that the Went-Cholodny theory for the mediation of tropisms is valid for dicot stems. Also consistent with the theory, an auxin asymmetry ratio of 2.5 was observed when wrong-way gravitropic curvature developed following application of a high level of auxin. In addition to reversing the asymmetry of elongation, the large supplement of auxin resulted in lower net elongation. Previous data established that ethylene is not involved in this decrease of growth as a function of increasing level of auxin. PMID:11537450

Cerebral arteriovenous malformation

MedlinePlus

AVM - cerebral; Arteriovenous hemangioma; Stroke - AVM; Hemorrhagic stroke - AVM ... The cause of cerebral AVM is unknown. An AVM occurs when arteries in the brain connect directly to nearby veins without having the ...

Aging and Cerebral Palsy.

ERIC Educational Resources Information Center

Networker, 1993

1993-01-01

This special edition of "The Networker" contains several articles focusing on aging and cerebral palsy (CP). "Aging and Cerebral Palsy: Pathways to Successful Aging" (Jenny C. Overeynder) reports on the National Invitational Colloquium on Aging and Cerebral Palsy held in April 1993. "Observations from an Observer" (Kathleen K. Barrett) describes…

Disentangling the Relationship between Hemispheric Asymmetry and Cognitive Performance

ERIC Educational Resources Information Center

Hirnstein, Marco; Leask, Stuart; Rose, Jonas; Hausmann, Markus

2010-01-01

It is widely believed that advantages of hemispheric asymmetries originated in better cognitive processing, hence it is often implied that the relationship between hemispheric asymmetry and cognitive performance is linearly positive: the higher the degree of lateralization in a specific cognitive domain, the better the performance in a…

The myosin ID pathway and left-right asymmetry in Drosophila.

PubMed

Géminard, Charles; González-Morales, Nicanor; Coutelis, Jean-Baptiste; Noselli, Stéphane

2014-06-01

Drosophila is a classical model to study body patterning, however left-right (L/R) asymmetry had remained unexplored, until recently. The discovery of the conserved myosin ID gene as a major determinant of L/R asymmetry has revealed a novel L/R pathway involving the actin cytoskeleton and the adherens junction. In this process, the HOX gene Abdominal-B plays a major role through the control of myosin ID expression and therefore symmetry breaking. In this review, we present organs and markers showing L/R asymmetry in Drosophila and discuss our current understanding of the underlying molecular genetic mechanisms. Drosophila represents a valuable model system revealing novel strategies to establish L/R asymmetry in invertebrates and providing an evolutionary perspective to the problem of laterality in bilateria. © 2014 Wiley Periodicals, Inc.

Sex differences in oral asymmetries during wordrepetition.

PubMed

Hausmann, M; Behrendt-Körbitz, S; Kautz, H; Lamm, C; Radelt, F; Güntürkün, O

1998-12-01

During speech production the right side of the mouth is opened to a larger degree in most people. This facial asymmetry is thought to be related to a left hemisphere dominance in language processing and/or motor programming. We investigated asymmetrical lip separations during discrete or serial word productions in right handed persons. The results revealed a right sided lip separation bias in both genders during discrete word production in which the words had to be uttered once. As soon as the words had to be produced continuously, however, a clear sex difference appeared with males having the usual right bias but females now showing no clear asymmetry, with a tendency for larger lip separations on the left side. These results suggest the existence of two separate neural systems from which one controls the discrete task and which is left hemisphere dominant in both genders. The other is probably involved in serial word productions and shows a sex difference with regard to its asymmetry pattern.

Cranium asymmetry in a modern Greek population sample of known age and sex.

PubMed

Chovalopoulou, Maria-Eleni; Papageorgopoulou, Christina; Bertsatos, Andreas

2017-05-01

The aim of this paper is to evaluate and quantify cranium asymmetry, sexual differences in the set of individual asymmetry scores, and the relationship between fluctuating asymmetry and age, in a modern Greek population sample. In addition, we test for the developmental origins of health and disease hypothesis by assessing the correlation between fluctuating asymmetry and cause of death. The study sample consisted of 173 crania of known sex and adult age (92 males, 81 females) belonging to individuals who lived in Greece during the twentieth century. The three-dimensional coordinates of 77 ectocranial landmarks were digitized using a Microscribe 3DX contact digitizer and landmark configurations were analyzed using the generalized least-squares Procrustes method. Regarding directional asymmetry, the results show that the human skull has a tendency for a left-side excess for the Greek population. No significant directional asymmetry differences between the sexes are found. The highest levels of fluctuating asymmetry for both sexes are located on the skull base. The levels of fluctuating asymmetry in all cranial regions appear higher for males than females. Nevertheless, these differences do not present any statistical significance between sexes. Additionally, there is no relationship between fluctuating asymmetry scores and age for both males and females. Finally, the results of this study could not confirm that early development has a significant impact on adult health outcomes.

Complementary therapies for depression: an overview.

PubMed

Ernst, E; Rand, J I; Stevinson, C

1998-11-01

Depression is one of the most common reasons for using complementary and alternative therapies. The aim of this article is to provide an overview of the evidence available on the treatment of depression with complementary therapies. Systematic literature searches were performed using several databases, reference list searching, and inquiry to colleagues. Data extraction followed a predefined protocol. The amount of rigorous scientific data to support the efficacy of complementary therapies in the treatment of depression is extremely limited. The areas with the most evidence for beneficial effects are exercise, herbal therapy (Hypericum perforatum), and, to a lesser extent, acupuncture and relaxation therapies. There is a need for further research involving randomized controlled trials into the efficacy of complementary and alternative therapies in the treatment of depression.

Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rumsey, J.M.; Duara, R.; Grady, C.

The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic ratesmore » (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.« less

[Cerebral protection].

PubMed

Cattaneo, A D

1993-09-01

Cerebral protection means prevention of cerebral neuronal damage. Severe brain damage extinguishes the very "human" functions such as speech, consciousness, intellectual capacity, and emotional integrity. Many pathologic conditions may inflict injuries to the brain, therefore the protection and salvage of cerebral neuronal function must be the top priorities in the care of critically ill patients. Brain tissue has unusually high energy requirements, its stores of energy metabolites are small and, as a result, the brain is totally dependent on a continuous supply of substrates and oxygen, via the circulation. In complete global ischemia (cardiac arrest) reperfusion is characterized by an immediate reactive hyperemia followed within 20-30 min by a delayed hypoperfusion state. It has been postulated that the latter contributes to the ultimate neurologic outcome. In focal ischemia (stroke) the primary focus of necrosis is encircled by an area (ischemic penumbra) that is underperfused and contains neurotoxic substances such as free radicals, prostaglandins, calcium, and excitatory neurotransmitters. The variety of therapeutic effort that have addressed the question of protecting the brain reflects their limited success. 1) Barbiturates. After an initial enthusiastic endorsement by many clinicians and years of vigorous controversy, it can now be unequivocally stated that there is no place for barbiturate therapy following resuscitation from cardiac arrest. One presumed explanation for this negative statement is that cerebral metabolic suppression by barbiturates (and other anesthetics) is impossible in the absence of an active EEG. Conversely, in the event of incomplete ischemia EEG activity in usually present (albeit altered) and metabolic suppression and hence possibly protection can be induced with barbiturates. Indeed, most of the animal studies led to a number of recommendations for barbiturate therapy in man for incomplete ischemia. 2) Isoflurane. From a cerebral

Growth models and the expected distribution of fluctuating asymmetry

USGS Publications Warehouse

Graham, John H.; Shimizu, Kunio; Emlen, John M.; Freeman, D. Carl; Merkel, John

2003-01-01

Multiplicative error accounts for much of the size-scaling and leptokurtosis in fluctuating asymmetry. It arises when growth involves the addition of tissue to that which is already present. Such errors are lognormally distributed. The distribution of the difference between two lognormal variates is leptokurtic. If those two variates are correlated, then the asymmetry variance will scale with size. Inert tissues typically exhibit additive error and have a gamma distribution. Although their asymmetry variance does not exhibit size-scaling, the distribution of the difference between two gamma variates is nevertheless leptokurtic. Measurement error is also additive, but has a normal distribution. Thus, the measurement of fluctuating asymmetry may involve the mixing of additive and multiplicative error. When errors are multiplicative, we recommend computing log E(l) − log E(r), the difference between the logarithms of the expected values of left and right sides, even when size-scaling is not obvious. If l and r are lognormally distributed, and measurement error is nil, the resulting distribution will be normal, and multiplicative error will not confound size-related changes in asymmetry. When errors are additive, such a transformation to remove size-scaling is unnecessary. Nevertheless, the distribution of l − r may still be leptokurtic.

Voxel-wise grey matter asymmetry analysis in left- and right-handers.

PubMed

Ocklenburg, Sebastian; Friedrich, Patrick; Güntürkün, Onur; Genç, Erhan

2016-10-28

Handedness is thought to originate in the brain, but identifying its structural correlates in the cortex has yielded surprisingly incoherent results. One idea proclaimed by several authors is that structural grey matter asymmetries might underlie handedness. While some authors have found significant associations with handedness in different brain areas (e.g. in the central sulcus and precentral sulcus), others have failed to identify such associations. One method used by many researchers to determine structural grey matter asymmetries is voxel based morphometry (VBM). However, it has recently been suggested that the standard VBM protocol might not be ideal to assess structural grey matter asymmetries, as it establishes accurate voxel-wise correspondence across individuals but not across both hemispheres. This could potentially lead to biased and incoherent results. Recently, a new toolbox specifically geared at assessing structural asymmetries and involving accurate voxel-wise correspondence across hemispheres has been published [F. Kurth, C. Gaser, E. Luders. A 12-step user guide for analyzing voxel-wise gray matter asymmetries in statistical parametric mapping (SPM), Nat Protoc 10 (2015), 293-304]. Here, we used this new toolbox to re-assess grey matter asymmetry differences in left- vs. right-handers and linked them to quantitative measures of hand preference and hand skill. While we identified several significant left-right asymmetries in the overall sample, no difference between left- and right-handers reached significance after correction for multiple comparisons. These findings indicate that the structural brain correlates of handedness are unlikely to be rooted in macroscopic grey matter area differences that can be assessed with VBM. Future studies should focus on other potential structural correlates of handedness, e.g. structural white matter asymmetries. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

SIMULATION STUDY OF HEMISPHERIC PHASE-ASYMMETRY IN THE SOLAR CYCLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shukuya, D.; Kusano, K., E-mail: kusano@nagoya-u.jp

2017-01-20

Observations of the Sun suggest that solar activities systematically create north–south hemispheric asymmetries. For instance, the hemisphere in which sunspot activity is more active tends to switch after the early half of each solar cycle. Svalgaard and Kamide recently pointed out that the time gaps of polar field reversal between the northern and southern hemispheres are simply consequences of the asymmetry of sunspot activity. However, the mechanism underlying the asymmetric feature in solar cycle activity is not yet well understood. In this paper, in order to explain the cause of the asymmetry from the theoretical point of view, we investigatemore » the relationship between the dipole- and quadrupole-type components of the magnetic field in the solar cycle using the mean-field theory based on the flux transport dynamo model. As a result, we found that there are two different attractors of the solar cycle, in which either the north or the south polar field is first reversed, and that the flux transport dynamo model explains well the phase-asymmetry of sunspot activity and the polar field reversal without any ad hoc source of asymmetry.« less

Hemispheric asymmetry and theory of mind: is there an association?

PubMed

Herzig, Daniela A; Sullivan, Sarah; Evans, Jonathan; Corcoran, Rhiannon; Mohr, Christine

2012-01-01

In autism and schizophrenia attenuated/atypical functional hemispheric asymmetry and theory of mind impairments have been reported, suggesting common underlying neuroscientific correlates. We here investigated whether impaired theory of mind performance is associated with attenuated/atypical hemispheric asymmetry. An association may explain the co-occurrence of both dysfunctions in psychiatric populations. Healthy participants (n=129) performed a left hemisphere (lateralised lexical decision task) and right hemisphere (lateralised face decision task) dominant task as well as a visual cartoon task to assess theory of mind performance. Linear regression analyses revealed inconsistent associations between theory of mind performance and functional hemisphere asymmetry: enhanced theory of mind performance was only associated with (1) faster right hemisphere language processing, and (2) reduced right hemisphere dominance for face processing (men only). The majority of non-significant findings suggest that theory of mind and functional hemispheric asymmetry are unrelated. Instead of "overinterpreting" the two significant results, discrepancies in the previous literature relating to the problem of the theory of mind concept, the variety of tasks, and the lack of normative data are discussed. We also suggest how future studies could explore a possible link between hemispheric asymmetry and theory of mind.

Tidal asymmetry in a funnel-shaped estuary with mixed semidiurnal tides

NASA Astrophysics Data System (ADS)

Gong, Wenping; Schuttelaars, Henk; Zhang, Heng

2016-05-01

Different types of tidal asymmetry (see review of de Swart and Zimmerman Annu Rev Fluid Mech 41: 203-229, 2009) are examined in this study. We distinguish three types of tidal asymmetry: duration and magnitude differences between flood and ebb tidal flow, duration difference between the rising and falling tides. For waterborne substance transport, the first two asymmetries are important while the last one is not. In this study, we take the Huangmaohai Estuary (HE), Pearl River Delta, China as an example to examine the spatio-temporal variations of the tidal asymmetry in a mixed semidiurnal tidal regime and to explain them by investigating the associated mechanisms. The methodology defining the tidal duration asymmetry and velocity skewness, proposed by Nidzieko (J Geophys Res 115: C08006. doi: 10.1029/2009JC005864 , 2010) and synthesized by Song et al. (J Geophys Res 116: C12007. doi: 10.1029/2011JC007270 , 2011), is utilized here and referred to as tidal duration asymmetry (TDA) and flow velocity asymmetry (FVA), respectively. The methodology is further used to quantify the flow duration asymmetry (FDA). A positive asymmetry means a shorter duration of low water slack for FDA, a shorter duration of the rising tide for TDA, and a flood dominance for FVA and vice versa. The Regional Ocean Modeling System (ROMS) model is used to provide relatively long-term water elevation and velocity data and to conduct diagnostic experiments. In the HE, the main tidal constituents are diurnal tides K 1, O 1 and semidiurnal tides M 2 and S 2. The interaction among the diurnal and semidiurnal tides generates a negative tidal asymmetry, while the interactions among semidiurnal tides and their overtides or compound tides result in a positive tidal asymmetry. The

Frontal alpha asymmetry neurofeedback for the reduction of negative affect and anxiety.

PubMed

Mennella, Rocco; Patron, Elisabetta; Palomba, Daniela

2017-05-01

Frontal alpha asymmetry has been proposed to underlie the balance between approach and withdrawal motivation associated to each individual's affective style. Neurofeedback of EEG frontal alpha asymmetry represents a promising tool to reduce negative affect, although its specific effects on left/right frontal activity and approach/withdrawal motivation are still unclear. The present study employed a neurofeedback training to increase frontal alpha asymmetry (right - left), in order to evaluate discrete changes in alpha power at left and right sites, as well as in positive and negative affect, anxiety and depression. Thirty-two right-handed females were randomly assigned to receive either the neurofeedback on frontal alpha asymmetry, or an active control training (N = 16 in each group). The asymmetry group showed an increase in alpha asymmetry driven by higher alpha at the right site (p < 0.001), as well as a coherent reduction in both negative affect and anxiety symptoms (ps < 0.05), from pre-to post-training. No training-specific modulation emerged for positive affect and depressive symptoms. These findings provide a strong rationale for the use of frontal alpha asymmetry neurofeedback for the reduction of negative affect and anxiety in clinical settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Changes of kinematics parameters of pelvis during walking under the influence of means facilitates treatment of cerebral palsied children.

PubMed

Czupryna, Krzysztof; Nowotny, Janusz

2012-01-01

Physiological human gait is characterized by tree-dimensional pelvis movements, which make that gait is smooth and does not require excessive energy expenditure. In children with cerebral palsy determinants of the pelvis may be affected, mainly due to pathological afferent synergisms. Therefore many specialists is looking for ways to improve this situation. The aim of this study was to verify whether the use of botulinium toxin or inhibitive casts affects the kinematic parameters of the pelvis during the gait of children with hemiparetic form of cerebral palsy. The study involved 34 hemiparetic children with cerebral palsy aged 7-14 years who reached the capacity of walking. All were improving by neurodevelop-mental treatment according to NDT-Bobath method. Two groups were created. In the first group inhibiting casting was used in 16 children. In the second group botulinium toxin was injected in 18 children. Gait analysis was performed before and after using those type of treatment. Ultrasonic CMS-HS system (Zebris) was used for three dimensional gait analysis. Despite of the characteristic for hemiplegic gait pattern asymmetry, various ab-normalities of pelvis kinematic parameters were observed. Gait symmetry was improved aafter the treatment. Using inhibiting casts also improved kinematic parameters of the pelvis, especially in those children who are found deficit of decreasing and rotation of the pelvis. 1) The use of Btx-A or inhibitive casts results in improving temporal- spatial parameters of gait of cerebral palsied children with hemiparesis. 2) The improvement of kinematic pelvis parameters are obtained through the use of inhibitive casts, while the use of Btx-A does not have a significant impact on them.

Changes of kinematics parameters of pelvis during walking under the influence of means facilitates treatment of cerebral palsied children.

PubMed

Czupryna, Krzysztof; Nowotny, Janusz

2012-01-01

Physiological human gait is characterized by changes of foot and knee angle that make the gait efficient and not require excessive energy expenditure. In cerebral palsied children, the foot-knee relationship is disturbed by pathological synergies. Therefore, ways to improve this situation are sought. The aim of the study was to verify whether and how well the use of botulinum toxin or inhibitive casts alters the behaviour of the foot-knee complex in cerebral palsy gait. The study involved 34 hemiparetic children with cerebral palsy aged 7-14 years who were able to walk unassisted. Neurodevelopmental treatment according to the NDT-Bobath method was given to all the children. Two groups were formed. In the first group of 16 children, inhibitive castings were used. The second group of 18 children received Btx-A injections. Gait analysis was performed at baseline and one month after administering these additional treatments. The CMS-HS ultrasonic system (Zebris) was used for three dimensional gait analysis. Apart from the pattern asymmetry characteristic of a hemiplegic gait, various pronounced abnormalities of the foot-knee complex were observed. Following treatment, gait symmetry improved in both groups as did the position of the hemiparetic foot in the mid-support phase. In the inhibitive casting groups, similar improvements were also observed in the initial contact phase. In the knee, greater improvement in knee was noted in the Btx-A group. Btx-A injections or inhibitive casts improve gait parameters in cerebral palsied children. This improvement is individual and seen in different stages of the support phase, but of similar magnitude following the use of either treatment. Achieving simultaneous improvement in the knee and foot is difficult.

Auditory cortex asymmetry, altered minicolumn spacing and absence of ageing effects in schizophrenia

PubMed Central

Casanova, Manuel F.; Switala, Andy E.; Crow, Timothy J.

2008-01-01

The superior temporal gyrus, which contains the auditory cortex, including the planum temporale, is the most consistently altered neocortical structure in schizophrenia (Shenton ME, Dickey CC, Frumin M, McCarley RW. A review of MRI findings in schizophrenia. Schizophr Res 2001; 49: 1–52). Auditory hallucinations are associated with abnormalities in this region and activation in Heschl's gyrus. Our review of 34 MRI and 5 post-mortem studies of planum temporale reveals that half of those measuring region size reported a change in schizophrenia, usually consistent with a reduction in the left hemisphere and a relative increase in the right hemisphere. Furthermore, female subjects are under-represented in the literature and insight from sex differences may be lost. Here we present evidence from post-mortem brain (N = 21 patients, compared with 17 previously reported controls) that normal age-associated changes in planum temporale are not found in schizophrenia. These age-associated differences are reported in an adult population (age range 29–90 years) and were not found in the primary auditory cortex of Heschl's gyrus, indicating that they are selective to the more plastic regions of association cortex involved in cognition. Areas and volumes of Heschl's gyrus and planum temporale and the separation of the minicolumns that are held to be the structural units of the cerebral cortex were assessed in patients. Minicolumn distribution in planum temporale and Heschl's gyrus was assessed on Nissl-stained sections by semi-automated microscope image analysis. The cortical surface area of planum temporale in the left hemisphere (usually asymmetrically larger) was positively correlated with its constituent minicolumn spacing in patients and controls. Surface area asymmetry of planum temporale was reduced in patients with schizophrenia by a reduction in the left hemisphere (F = 7.7, df 1,32, P < 0.01). The relationship between cortical asymmetry and the connecting

Visuospatial Asymmetries Arise from Differences in the Onset Time of Perceptual Evidence Accumulation.

PubMed

Newman, Daniel P; Loughnane, Gerard M; Kelly, Simon P; O'Connell, Redmond G; Bellgrove, Mark A

2017-03-22

Healthy subjects tend to exhibit a bias of visual attention whereby left hemifield stimuli are processed more quickly and accurately than stimuli appearing in the right hemifield. It has long been held that this phenomenon arises from the dominant role of the right cerebral hemisphere in regulating attention. However, methods that would enable more precise understanding of the mechanisms underpinning visuospatial bias have remained elusive. We sought to finely trace the temporal evolution of spatial biases by leveraging a novel bilateral dot motion detection paradigm. In combination with electroencephalography, this paradigm enables researchers to isolate discrete neural signals reflecting the key neural processes needed for making these detection decisions. These include signals for spatial attention, early target selection, evidence accumulation, and motor preparation. Using this method, we established that three key neural markers accounted for unique between-subject variation in visuospatial bias: hemispheric asymmetry in posterior α power measured before target onset, which is related to the distribution of preparatory attention across the visual field; asymmetry in the peak latency of the early N2c target-selection signal; and, finally, asymmetry in the onset time of the subsequent neural evidence-accumulation process with earlier onsets for left hemifield targets. Our development of a single paradigm to dissociate distinct processing components that track the temporal evolution of spatial biases not only advances our understanding of the neural mechanisms underpinning normal visuospatial attention bias, but may also in the future aid differential diagnoses in disorders of spatial attention. SIGNIFICANCE STATEMENT The significance of this research is twofold. First, it shows that individual differences in how humans direct their attention between left and right space reflects physiological differences in how early the brain starts to accumulate evidence for

Yield asymmetry design of magnesium alloys by integrated computational materials engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dongsheng; Joshi, Vineet; Lavender, Curt

2013-11-01

Deformation asymmetry of magnesium alloys is an important factor on machine design in the automobile industry. Represented by the ratio of compressive yield stress (CYS) against tensile yield stress (TYS), deformation asymmetry is strongly related to texture and grain size. A polycrystalline viscoplasticity model, modified intermediate Φ-model, is used to predict the deformation behavior of magnesium alloys with different grain sizes. Validated with experimental results, integrated computational materials engineering is applied to find out the route in achieving desired asymmetry via thermomechanical processing. For example, CYS/TYS in rolled texture is smaller than 1 under different loading directions. In other textures,more » such as extruded texture, CYS/TYS is large along the normal direction. Starting from rolled texture, asymmetry will increase to close to 1 along the rolling direction after being compressed to a strain of 0.2. Our modified Φ-model also shows that grain refinement increases CYS/TYS. Along with texture control, grain refinement also can optimize the yield asymmetry. After the grain size decreases to a critical value, CYS/TYS reaches to 1 because CYS increases much faster than TYS. By tailoring the microstructure using texture control and grain refinement, it is achievable to optimize yield asymmetry in wrought magnesium alloys.« less

Scale-dependent cyclone-anticyclone asymmetry in a forced rotating turbulence experiment

NASA Astrophysics Data System (ADS)

Gallet, B.; Campagne, A.; Cortet, P.-P.; Moisy, F.

2014-03-01

We characterize the statistical and geometrical properties of the cyclone-anticyclone asymmetry in a statistically steady forced rotating turbulence experiment. Turbulence is generated by a set of vertical flaps which continuously inject velocity fluctuations towards the center of a tank mounted on a rotating platform. We first characterize the cyclone-anticyclone asymmetry from conventional single-point vorticity statistics. We propose a phenomenological model to explain the emergence of the asymmetry in the experiment, from which we predict scaling laws for the root-mean-square velocity in good agreement with the experimental data. We further quantify the cyclone-anticyclone asymmetry using a set of third-order two-point velocity correlations. We focus on the correlations which are nonzero only if the cyclone-anticyclone symmetry is broken. They offer two advantages over single-point vorticity statistics: first, they are defined from velocity measurements only, so an accurate resolution of the Kolmogorov scale is not required; second, they provide information on the scale-dependence of the cyclone-anticyclone asymmetry. We compute these correlation functions analytically for a random distribution of independent identical vortices. These model correlations describe well the experimental ones, indicating that the cyclone-anticyclone asymmetry is dominated by the large-scale long-lived cyclones.

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

NASA Astrophysics Data System (ADS)

Aaltonen, T.; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Askew, A.; Atkins, S.; Auerbach, B.; Augsten, K.; Aurisano, A.; Aushev, V.; Aushev, Y.; Avila, C.; Azfar, F.; Badaud, F.; Badgett, W.; Bae, T.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barbaro-Galtieri, A.; Barberis, E.; Baringer, P.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartlett, J. F.; Bartos, P.; Bassler, U.; Bauce, M.; Bazterra, V.; Bean, A.; Bedeschi, F.; Begalli, M.; Behari, S.; Bellantoni, L.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Bhatti, A.; Bland, K. R.; Blazey, G.; Blessing, S.; Bloom, K.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bortoletto, D.; Borysova, M.; Boudreau, J.; Boveia, A.; Brandt, A.; Brandt, O.; Brigliadori, L.; Brochmann, M.; Brock, R.; Bromberg, C.; Bross, A.; Brown, D.; Brucken, E.; Bu, X. B.; Budagov, J.; Budd, H. S.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buszello, C. P.; Butti, P.; Buzatu, A.; Calamba, A.; Camacho-Pérez, E.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Casey, B. C. K.; Castilla-Valdez, H.; Castro, A.; Catastini, P.; Caughron, S.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapelain, A.; Chapon, E.; Chen, G.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Cho, S. W.; Choi, S.; Chokheli, D.; Choudhary, B.; Cihangir, S.; Claes, D.; Clark, A.; Clarke, C.; Clutter, J.; Convery, M. E.; Conway, J.; Cooke, M.; Cooper, W. E.; Corbo, M.; Corcoran, M.; Cordelli, M.; Couderc, F.; Cousinou, M.-C.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; Cuth, J.; Cutts, D.; Das, A.; d'Ascenzo, N.; Datta, M.; Davies, G.; de Barbaro, P.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Demortier, L.; Deninno, M.; Denisov, D.; Denisov, S. P.; D'Errico, M.; Desai, S.; Deterre, C.; DeVaughan, K.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dittmann, J. R.; Dominguez, A.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Drutskoy, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Ebina, K.; Edgar, R.; Edmunds, D.; Elagin, A.; Ellison, J.; Elvira, V. D.; Enari, Y.; Erbacher, R.; Errede, S.; Esham, B.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Farrington, S.; Fauré, A.; Feng, L.; Ferbel, T.; Fernández Ramos, J. P.; Fiedler, F.; Field, R.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Flanagan, G.; Forrest, R.; Fortner, M.; Fox, H.; Franc, J.; Franklin, M.; Freeman, J. C.; Frisch, H.; Fuess, S.; Funakoshi, Y.; Galloni, C.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Garfinkel, A. F.; Garosi, P.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gerberich, H.; Gerchtein, E.; Gershtein, Y.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Ginther, G.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gogota, O.; Gold, M.; Goldin, D.; Golossanov, A.; Golovanov, G.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grosso-Pilcher, C.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Guimaraes da Costa, J.; Gutierrez, G.; Gutierrez, P.; Hahn, S. R.; Haley, J.; Han, J. Y.; Han, L.; Happacher, F.; Hara, K.; Harder, K.; Hare, M.; Harel, A.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hauptman, J. M.; Hays, C.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinrich, J.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herndon, M.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hocker, A.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Hong, Z.; Hopkins, W.; Hou, S.; Howley, I.; Hubacek, Z.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Introzzi, G.; Iori, M.; Ito, A. S.; Ivanov, A.; Jabeen, S.; Jaffré, M.; James, E.; Jang, D.; Jayasinghe, A.; Jayatilaka, B.; Jeon, E. J.; Jeong, M. S.; Jesik, R.; Jiang, P.; Jindariani, S.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jones, M.; Jonsson, P.; Joo, K. K.; Joshi, J.; Jun, S. Y.; Jung, A. W.; Junk, T. R.; Juste, A.; Kajfasz, E.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Karmanov, D.; Kasmi, A.; Kato, Y.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Ketchum, W.; Keung, J.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Kiselevich, I.; Kohli, J. M.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kozelov, A. V.; Kraus, J.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kumar, A.; Kupco, A.; Kurata, M.; Kurča, T.; Kuzmin, V. A.; Laasanen, A. T.; Lammel, S.; Lammers, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lebrun, P.; Lee, H. S.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Leo, S.; Leone, S.; Lewis, J. D.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Limosani, A.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipeles, E.; Lipton, R.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Liu, Y.; Lobodenko, A.; Lockwitz, S.; Loginov, A.; Lokajicek, M.; Lopes de Sa, R.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Luna-Garcia, R.; Lungu, G.; Lyon, A. L.; Lys, J.; Lysak, R.; Maciel, A. K. A.; Madar, R.; Madrak, R.; Maestro, P.; Magaña-Villalba, R.; Malik, S.; Malik, S.; Malyshev, V. L.; Manca, G.; Manousakis-Katsikakis, A.; Mansour, J.; Marchese, L.; Margaroli, F.; Marino, P.; Martínez-Ortega, J.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McCarthy, R.; McGivern, C. L.; McNulty, R.; Mehta, A.; Mehtala, P.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Mesropian, C.; Meyer, A.; Meyer, J.; Miao, T.; Miconi, F.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondal, N. K.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Mulhearn, M.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nagy, E.; Nakano, I.; Napier, A.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Nett, J.; Neustroev, P.; Nguyen, H. T.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Nunnemann, T.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Okusawa, T.; Orava, R.; Orduna, J.; Ortolan, L.; Osman, N.; Pagliarone, C.; Pal, A.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parashar, N.; Parihar, V.; Park, S. K.; Parker, W.; Partridge, R.; Parua, N.; Patwa, A.; Pauletta, G.; Paulini, M.; Paus, C.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pleier, M.-A.; Podstavkov, V. M.; Pondrom, L.; Popov, A. V.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prewitt, M.; Price, D.; Prokopenko, N.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ripp-Baudot, I.; Ristori, L.; Rizatdinova, F.; Robson, A.; Rodriguez, T.; Rolli, S.; Rominsky, M.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sajot, G.; Sakumoto, W. K.; Sakurai, Y.; Sánchez-Hernández, A.; Sanders, M. P.; Santi, L.; Santos, A. S.; Sato, K.; Savage, G.; Saveliev, V.; Savitskyi, M.; Savoy-Navarro, A.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlabach, P.; Schmidt, E. E.; Schott, M.; Schwanenberger, C.; Schwarz, T.; Schwienhorst, R.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Sekaric, J.; Semenov, A.; Severini, H.; Sforza, F.; Shabalina, E.; Shalhout, S. Z.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shkola, O.; Shochet, M.; Shreyber-Tecker, I.; Simak, V.; Simonenko, A.; Skubic, P.; Slattery, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Song, H.; Sonnenschein, L.; Sorin, V.; Soustruznik, K.; St. Denis, R.; Stancari, M.; Stark, J.; Stefaniuk, N.; Stentz, D.; Stoyanova, D. A.; Strauss, M.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Suter, L.; Svoisky, P.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Titov, M.; Toback, D.; Tokar, S.; Tokmenin, V. V.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Ukegawa, F.; Uozumi, S.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Vázquez, F.; Velev, G.; Vellidis, C.; Verkheev, A. Y.; Vernieri, C.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vidal, M.; Vilanova, D.; Vilar, R.; Vizán, J.; Vogel, M.; Vokac, P.; Volpi, G.; Wagner, P.; Wahl, H. D.; Wallny, R.; Wang, M. H. L. S.; Wang, S. M.; Warchol, J.; Waters, D.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Williams, M. R. J.; Wilson, G. W.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wobisch, M.; Wolbers, S.; Wolfmeister, H.; Wood, D. R.; Wright, T.; Wu, X.; Wu, Z.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yamamoto, K.; Yamato, D.; Yang, S.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yeh, G. P.; Yi, K.; Yin, H.; Yip, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Youn, S. W.; Yu, G. B.; Yu, I.; Yu, J. M.; Zanetti, A. M.; Zeng, Y.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhou, C.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.; Zucchelli, S.; CDF Collaboration

2018-01-01

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of √{s }=1.96 TeV . We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is AFBt t ¯=0.128 ±0.025 . The combined inclusive and differential asymmetries are consistent with recent standard model predictions.

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron.

PubMed

Aaltonen, T; Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Agnew, J P; Alexeev, G D; Alkhazov, G; Alton, A; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Askew, A; Atkins, S; Auerbach, B; Augsten, K; Aurisano, A; Aushev, V; Aushev, Y; Avila, C; Azfar, F; Badaud, F; Badgett, W; Bae, T; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barbaro-Galtieri, A; Barberis, E; Baringer, P; Barnes, V E; Barnett, B A; Barria, P; Bartlett, J F; Bartos, P; Bassler, U; Bauce, M; Bazterra, V; Bean, A; Bedeschi, F; Begalli, M; Behari, S; Bellantoni, L; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Bhatti, A; Bland, K R; Blazey, G; Blessing, S; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bortoletto, D; Borysova, M; Boudreau, J; Boveia, A; Brandt, A; Brandt, O; Brigliadori, L; Brochmann, M; Brock, R; Bromberg, C; Bross, A; Brown, D; Brucken, E; Bu, X B; Budagov, J; Budd, H S; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burkett, K; Busetto, G; Bussey, P; Buszello, C P; Butti, P; Buzatu, A; Calamba, A; Camacho-Pérez, E; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Casey, B C K; Castilla-Valdez, H; Castro, A; Catastini, P; Caughron, S; Cauz, D; Cavaliere, V; Cerri, A; Cerrito, L; Chakrabarti, S; Chan, K M; Chandra, A; Chapelain, A; Chapon, E; Chen, G; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Cho, S W; Choi, S; Chokheli, D; Choudhary, B; Cihangir, S; Claes, D; Clark, A; Clarke, C; Clutter, J; Convery, M E; Conway, J; Cooke, M; Cooper, W E; Corbo, M; Corcoran, M; Cordelli, M; Couderc, F; Cousinou, M-C; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; Cuth, J; Cutts, D; Das, A; d'Ascenzo, N; Datta, M; Davies, G; de Barbaro, P; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Demortier, L; Deninno, M; Denisov, D; Denisov, S P; D'Errico, M; Desai, S; Deterre, C; DeVaughan, K; Devoto, F; Di Canto, A; Di Ruzza, B; Diehl, H T; Diesburg, M; Ding, P F; Dittmann, J R; Dominguez, A; Donati, S; D'Onofrio, M; Dorigo, M; Driutti, A; Drutskoy, A; Dubey, A; Dudko, L V; Duperrin, A; Dutt, S; Eads, M; Ebina, K; Edgar, R; Edmunds, D; Elagin, A; Ellison, J; Elvira, V D; Enari, Y; Erbacher, R; Errede, S; Esham, B; Evans, H; Evdokimov, A; Evdokimov, V N; Farrington, S; Fauré, A; Feng, L; Ferbel, T; Fernández Ramos, J P; Fiedler, F; Field, R; Filthaut, F; Fisher, W; Fisk, H E; Flanagan, G; Forrest, R; Fortner, M; Fox, H; Franc, J; Franklin, M; Freeman, J C; Frisch, H; Fuess, S; Funakoshi, Y; Galloni, C; Garbincius, P H; Garcia-Bellido, A; García-González, J A; Garfinkel, A F; Garosi, P; Gavrilov, V; Geng, W; Gerber, C E; Gerberich, H; Gerchtein, E; Gershtein, Y; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Ginther, G; Giokaris, N; Giromini, P; Glagolev, V; Glenzinski, D; Gogota, O; Gold, M; Goldin, D; Golossanov, A; Golovanov, G; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grosso-Pilcher, C; Grünendahl, S; Grünewald, M W; Guillemin, T; Guimaraes da Costa, J; Gutierrez, G; Gutierrez, P; Hahn, S R; Haley, J; Han, J Y; Han, L; Happacher, F; Hara, K; Harder, K; Hare, M; Harel, A; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hauptman, J M; Hays, C; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinrich, J; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herndon, M; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hocker, A; Hoeneisen, B; Hogan, J; Hohlfeld, M; Holzbauer, J L; Hong, Z; Hopkins, W; Hou, S; Howley, I; Hubacek, Z; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Introzzi, G; Iori, M; Ito, A S; Ivanov, A; Jabeen, S; Jaffré, M; James, E; Jang, D; Jayasinghe, A; Jayatilaka, B; Jeon, E J; Jeong, M S; Jesik, R; Jiang, P; Jindariani, S; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jones, M; Jonsson, P; Joo, K K; Joshi, J; Jun, S Y; Jung, A W; Junk, T R; Juste, A; Kajfasz, E; Kambeitz, M; Kamon, T; Karchin, P E; Karmanov, D; Kasmi, A; Kato, Y; Katsanos, I; Kaur, M; Kehoe, R; Kermiche, S; Ketchum, W; Keung, J; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S H; Kim, S B; Kim, Y J; Kim, Y K; Kimura, N; Kirby, M; Kiselevich, I; Kohli, J M; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kozelov, A V; Kraus, J; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kumar, A; Kupco, A; Kurata, M; Kurča, T; Kuzmin, V A; Laasanen, A T; Lammel, S; Lammers, S; Lancaster, M; Lannon, K; Latino, G; Lebrun, P; Lee, H S; Lee, H S; Lee, J S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Leo, S; Leone, S; Lewis, J D; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Limosani, A; Lincoln, D; Linnemann, J; Lipaev, V V; Lipeles, E; Lipton, R; Lister, A; Liu, H; Liu, Q; Liu, T; Liu, Y; Lobodenko, A; Lockwitz, S; Loginov, A; Lokajicek, M; Lopes de Sa, R; Lucchesi, D; Lucà, A; Lueck, J; Lujan, P; Lukens, P; Luna-Garcia, R; Lungu, G; Lyon, A L; Lys, J; Lysak, R; Maciel, A K A; Madar, R; Madrak, R; Maestro, P; Magaña-Villalba, R; Malik, S; Malik, S; Malyshev, V L; Manca, G; Manousakis-Katsikakis, A; Mansour, J; Marchese, L; Margaroli, F; Marino, P; Martínez-Ortega, J; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McCarthy, R; McGivern, C L; McNulty, R; Mehta, A; Mehtala, P; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Mesropian, C; Meyer, A; Meyer, J; Miao, T; Miconi, F; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondal, N K; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Mulhearn, M; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nagy, E; Nakano, I; Napier, A; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Nett, J; Neustroev, P; Nguyen, H T; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Nunnemann, T; Oakes, L; Oh, S H; Oh, Y D; Okusawa, T; Orava, R; Orduna, J; Ortolan, L; Osman, N; Pagliarone, C; Pal, A; Palencia, E; Palni, P; Papadimitriou, V; Parashar, N; Parihar, V; Park, S K; Parker, W; Partridge, R; Parua, N; Patwa, A; Pauletta, G; Paulini, M; Paus, C; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pleier, M-A; Podstavkov, V M; Pondrom, L; Popov, A V; Poprocki, S; Potamianos, K; Pranko, A; Prewitt, M; Price, D; Prokopenko, N; Prokoshin, F; Ptohos, F; Punzi, G; Qian, J; Quadt, A; Quinn, B; Ratoff, P N; Razumov, I; Redondo Fernández, I; Renton, P; Rescigno, M; Rimondi, F; Ripp-Baudot, I; Ristori, L; Rizatdinova, F; Robson, A; Rodriguez, T; Rolli, S; Rominsky, M; Ronzani, M; Roser, R; Rosner, J L; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Sajot, G; Sakumoto, W K; Sakurai, Y; Sánchez-Hernández, A; Sanders, M P; Santi, L; Santos, A S; Sato, K; Savage, G; Saveliev, V; Savitskyi, M; Savoy-Navarro, A; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schlabach, P; Schmidt, E E; Schott, M; Schwanenberger, C; Schwarz, T; Schwienhorst, R; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Sekaric, J; Semenov, A; Severini, H; Sforza, F; Shabalina, E; Shalhout, S Z; Shary, V; Shaw, S; Shchukin, A A; Shears, T; Shepard, P F; Shimojima, M; Shkola, O; Shochet, M; Shreyber-Tecker, I; Simak, V; Simonenko, A; Skubic, P; Slattery, P; Sliwa, K; Smith, J R; Snider, F D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, H; Sonnenschein, L; Sorin, V; Soustruznik, K; St Denis, R; Stancari, M; Stark, J; Stefaniuk, N; Stentz, D; Stoyanova, D A; Strauss, M; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Suter, L; Svoisky, P; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Titov, M; Toback, D; Tokar, S; Tokmenin, V V; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Ukegawa, F; Uozumi, S; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Vázquez, F; Velev, G; Vellidis, C; Verkheev, A Y; Vernieri, C; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vidal, M; Vilanova, D; Vilar, R; Vizán, J; Vogel, M; Vokac, P; Volpi, G; Wagner, P; Wahl, H D; Wallny, R; Wang, M H L S; Wang, S M; Warchol, J; Waters, D; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Williams, M R J; Wilson, G W; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wobisch, M; Wolbers, S; Wolfmeister, H; Wood, D R; Wright, T; Wu, X; Wu, Z; Wyatt, T R; Xie, Y; Yamada, R; Yamamoto, K; Yamato, D; Yang, S; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yeh, G P; Yi, K; Yin, H; Yip, K; Yoh, J; Yorita, K; Yoshida, T; Youn, S W; Yu, G B; Yu, I; Yu, J M; Zanetti, A M; Zeng, Y; Zennamo, J; Zhao, T G; Zhou, B; Zhou, C; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zucchelli, S

2018-01-26

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A_{FB}^{tt[over ¯]}=0.128±0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.

Diagnostic ability of macular ganglion cell asymmetry for glaucoma.

PubMed

Hwang, Young Hoon; Ahn, Sang Il; Ko, Sung Ju

2015-11-01

Using spectral-domain optical coherence tomography (OCT), this study aims to investigate the glaucoma diagnostic ability of macular ganglion cell asymmetry analysis. A cross-sectional study was conducted. This study was performed to investigate glaucoma diagnostic ability of macular ganglion cell asymmetry analysis in eyes with various degrees of glaucoma. We enrolled 181 healthy eyes and 265 glaucomatous eyes. Glaucomatous eyes were subdivided into pre-perimetric, early, moderate and advanced-to-severe glaucoma based on visual field test results. For each eye, macular ganglion cell-inner plexiform layer (GCIPL) thickness was measured using OCT. Average GCIPL thickness, GCIPL thicknesses in superior and inferior hemispheres, absolute difference in GCIPL thickness between superior and inferior hemispheres and GCIPL asymmetry index calculated as the absolute value of log10 (inferior hemisphere thickness/superior hemisphere thickness) were analysed. Areas under the receiver operating characteristics curves (AUCs) of GCIPL parameter were calculated and compared. All of the GCIPL parameters showed good glaucoma diagnostic ability (AUCs ≥ 0.817, P < 0.01). AUCs of average, superior and inferior GCIPL thickness increased as the severity of glaucoma increased. GCIPL thickness difference and asymmetry index showed the highest AUCs in early and moderate glaucoma and lower AUCs in pre-perimetric and advanced-to-severe glaucoma. GCIPL thickness difference and asymmetry index showed better glaucoma diagnostic ability than other GCIPL parameters only in early stage of glaucoma (P < 0.05); in other stages, these parameters had similar to or worse glaucoma diagnostic ability than other GCIPL parameters. Macular ganglion cell asymmetry analysis showed good glaucoma diagnostic ability, especially in early-stage glaucoma. However, it has limited usefulness in other stages of glaucoma. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

Asymmetries for the Visual Expression and Perception of Speech

ERIC Educational Resources Information Center

Nicholls, Michael E. R.; Searle, Dara A.

2006-01-01

This study explored asymmetries for movement, expression and perception of visual speech. Sixteen dextral models were videoed as they articulated: "bat," "cat," "fat," and "sat." Measurements revealed that the right side of the mouth was opened wider and for a longer period than the left. The asymmetry was accentuated at the beginning and ends of…

Energy evolution for the Sivers asymmetries in hard processes

NASA Astrophysics Data System (ADS)

Sun, Peng; Yuan, Feng

2013-08-01

We investigate the energy evolution of the azimuthal spin asymmetries in semi-inclusive hadron production in deep inelastic scattering (SIDIS) and Drell-Yan lepton pair production in pp collisions. The scale dependence is evaluated by applying an approximate solution to the Collins-Soper-Sterman evolution equation at one-loop order, which is adequate for moderate Q2 variations. This describes well the unpolarized cross sections for the SIDIS and Drell-Yan process in the Q2 range of 2.4-100GeV2. A combined analysis of the Sivers asymmetries in SIDIS from HERMES and COMPASS experiments and the predictions for the Drell-Yan process at RHIC at S=200GeV are presented. We further extend to the Collins asymmetries and find, for the first time, a consistent description for HERMES/COMPASS and BELLE experiments with the evolution effects. We emphasize an important test of the evolution effects by studying di-hadron azimuthal asymmetry in e+e- annihilation at moderate energy range, such as at BEPC at S=4.6GeV.

Nonlinear growth dynamics and the origin of fluctuating asymmetry

USGS Publications Warehouse

Emlen, J.M.; Freeman, D.C.; Graham, J.H.

1993-01-01

The nonlinear, complex nature of biosynthesis magnifies the impacts of small, random perturbations on organism growth, leading to distortions in adaptive allometries and, in particular, to fluctuating asymmetry. These distortions can be partly checked by cell-cell and inter-body part feedback during growth and development, though the latter mechanism also may lead to complex patterns in right-left asymmetry. Stress can be expected to increase the degree to which random growth perturbations are magnified and may also result in disruption of the check mechanisms, thus exaggerating fluctuating asymmetry.The processes described not only provide one explanation for the existence of fluctuating asymmetry and its augmentation under stress, but suggest additional effects of stress as well. Specifically, stress is predicted to lead to decreased fractal dimension of bone sutures and branching structures in animals, and in increased dimension of growth trace patterns such as those found in mollusc shells and fish otoliths and scales.A basic yet broad primer on fractals and chaos is provided as background for the theoretical development in this manuscript.

Foot force production and asymmetries in elite rowers.

PubMed

Buckeridge, Erica M; Bull, Anthony M J; McGregor, Alison H

2014-03-01

The rowing stroke is a leg-driven action, in which forces developed by the lower limbs provide a large proportion of power delivered to the oars. In terms of both performance and injury, it is important to initiate each stroke with powerful and symmetrical loading of the foot stretchers. The aims of this study were to assess the reliability of foot force measured by footplates developed for the Concept2 indoor ergometer and to examine the magnitude and symmetry of bilateral foot forces in different groups of rowers. Five heavyweight female scullers, six heavyweight female sweep rowers, and six lightweight male (LWM) rowers performed an incremental step test on the Concept2 ergometer. Vertical, horizontal, and resultant forces were recorded bilaterally, and asymmetries were quantified using the absolute symmetry index. Foot force was measured with high consistency (coefficient of multiple determination > 0.976 +/- 0.010). Relative resultant, vertical, and horizontal forces were largest in LWM rowers, whilst average foot forces significantly increased across stroke rates for all three groups of rowers. Asymmetries ranged from 5.3% for average resultant force to 28.9% for timing of peak vertical force. Asymmetries were not sensitive to stroke rate or rowing group, however, large inter-subject variability in asymmetries was evident.

Investors’ risk attitudes and stock price fluctuation asymmetry

NASA Astrophysics Data System (ADS)

Zhang, Yu; Li, Honggang

2011-05-01

Price rise/fall asymmetry, which indicates enduring but modest rises and sudden short-term falls, is a ubiquitous phenomenon in stock markets throughout the world. Instead of the widely used time series method, we adopt inverse statistics from turbulence to analyze this asymmetry. To explore its underlying mechanism, we build a multi-agent model with two kinds of investors, which are specifically referred to as fundamentalists and chartists. Inspired by Kahneman and Tversky’s claim regarding peoples’ asymmetric psychological responses to the equivalent levels of gains and losses, we assume that investors take different risk attitudes to gains and losses and adopt different trading strategies. The simulation results of the model developed herein are consistent with empirical work, which may support our conjecture that investors’ asymmetric risk attitudes might be one origin of rise/fall asymmetry.

Genetic basis of human left-right asymmetry disorders.

PubMed

Deng, Hao; Xia, Hong; Deng, Sheng

2015-01-27

Humans and other vertebrates exhibit left-right (LR) asymmetric arrangement of the internal organs, and failure to establish normal LR asymmetry leads to internal laterality disorders, including situs inversus and heterotaxy. Situs inversus is complete mirror-imaged arrangement of the internal organs along LR axis, whereas heterotaxy is abnormal arrangement of the internal thoraco-abdominal organs across LR axis of the body, most of which are associated with complex cardiovascular malformations. Both disorders are genetically heterogeneous with reduced penetrance, presumably because of monogenic, polygenic or multifactorial causes. Research in genetics of LR asymmetry disorders has been extremely prolific over the past 17 years, and a series of loci and disease genes involved in situs inversus and heterotaxy have been described. The review highlights the classification, chromosomal abnormalities, pathogenic genes and the possible mechanism of human LR asymmetry disorders.

Cerebral hemodynamics at altitude: effects of hyperventilation and acclimatization on cerebral blood flow and oxygenation.

PubMed

Sanborn, Matthew R; Edsell, Mark E; Kim, Meeri N; Mesquita, Rickson; Putt, Mary E; Imray, Chris; Yow, Heng; Wilson, Mark H; Yodh, Arjun G; Grocott, Mike; Martin, Daniel S

2015-06-01

Alterations in cerebral blood flow (CBF) and cerebral oxygenation are implicated in altitude-associated diseases. We assessed the dynamic changes in CBF and peripheral and cerebral oxygenation engendered by ascent to altitude with partial acclimatization and hyperventilation using a combination of near-infrared spectroscopy, transcranial Doppler ultrasound, and diffuse correlation spectroscopy. Peripheral (Spo2) and cerebral (Scto2) oxygenation, end-tidal carbon dioxide (ETCO2), and cerebral hemodynamics were studied in 12 subjects using transcranial Doppler and diffuse correlation spectroscopy (DCS) at 75 m and then 2 days and 7 days after ascending to 4559 m above sea level. After obtaining baseline measurements, subjects hyperventilated to reduce baseline ETCO2 by 50%, and a further set of measurements were obtained. Cerebral oxygenation and peripheral oxygenation showed a divergent response, with cerebral oxygenation decreasing at day 2 and decreasing further at day 7 at altitude, whereas peripheral oxygenation decreased on day 2 before partially rebounding on day 7. Cerebral oxygenation decreased after hyperventilation at sea level (Scto2 from 68.8% to 63.5%; P<.001), increased after hyperventilation after 2 days at altitude (Scto2 from 65.6% to 69.9%; P=.001), and did not change after hyperventilation after 7 days at altitude (Scto2 from 62.2% to 63.3%; P=.35). An intensification of the normal cerebral hypocapnic vasoconstrictive response occurred after partial acclimatization in the setting of divergent peripheral and cerebral oxygenation. This may help explain why hyperventilation fails to improve cerebral oxygenation after partial acclimatization as it does after initial ascent. The use of DCS is feasible at altitude and provides a direct measure of CBF indices with high temporal resolution. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Functional asymmetry of pelvic floor innervation--myth or fact?

PubMed

Enck, Paul

2004-01-01

Neurophysiology of the pelvic floor is not completely understood yet. The importance of its symmetry and asymmetry of innervation has been pointed out lately. These facts have the clinical relevance in case of pelvic floor trauma or incontinence surgery. New techniques of EMG are necessary to confirm correlations between symptoms development and asymmetry of sphincter innervation.

[Complementary and alternative medicine in oncology].

PubMed

Hübner, J

2013-06-01

Complementary and alternative medicine are frequently used by cancer patients. The main benefit of complementary medicine is that it gives patients the chance to become active. Complementary therapy can reduce the side effects of conventional therapy. However, we have to give due consideration to side effects and interactions: the latter being able to reduce the effectiveness of cancer therapy and so to jeopardise the success of therapy. Therefore, complementary therapy should be managed by the oncologist. It is based on a common concept of cancerogenesis with conventional therapy. Complement therapy can be assessed in studies. Alternative medicine in contrast rejects common rules of evidence-based medicine. It starts from its own concepts of cancerogenesis, which is often in line with the thinking of lay persons. Alternative medicine is offered as either "alternative" to recommended cancer treatment or is used at the same time but without due regard for the interactions. Alternative medicine is a high risk to patients. In the following two parts of the article, the most important complementary and alternative therapies cancer patients use nowadays are presented and assessed according to published evidence.

Effects of fatigue on bilateral ground reaction force asymmetries during the squat exercise.

PubMed

Hodges, Stephanie J; Patrick, Ryan J; Reiser, Raoul F

2011-11-01

Physical performance and injury risk have been related to functional asymmetries of the lower extremity. The effect of fatigue on asymmetries is not well understood. The goal of this investigation was to examine asymmetries during fatiguing repetitions and sets of the free-weight barbell back squat exercise. Seventeen healthy recreationally trained men and women (age = 22.3 ± 2.5 years; body mass = 73.4 ± 13.8 kg; squat 8 repetition maximum [8RM] = 113 ± 35% body mass [mean ± SD]) performed 5 sets of 8 repetitions with 90% 8RM while recording bilateral vertical ground reaction force (GRFv). The GRFv asymmetry during the first 2 (R1 and R2) and the last 2 (R7 and R8) repetitions of each set was calculated by subtracting the % load on the right foot from that of the left foot. Most subjects placed more load on their left foot (also their preferred non-kicking foot). Average absolute asymmetry level across all sets was 4.3 ± 2.5 and 3.6 ± 2.3% for R1 and R2 and R7 and R8, respectively. There were no effects of fatigue on GRFv asymmetries in whole-group analysis (n = 17). However, when initially highly symmetric subjects (±1.7% Left-Right) were removed, average absolute GRFv asymmetry dropped from the beginning to the end of a set (n = 12, p = 0.044) as did peak instantaneous GRFv asymmetry when exploring general shifts toward the left or right leg (n = 12, p = 0.042). The GRFv asymmetries were highly repeatable for 8 subjects that repeated the protocol (Cronbach's α ≥ 0.733, p ≤ 0.056). These results suggest that functional asymmetries, though low, are present in healthy people during the squat exercise and remain consistent. Asymmetries do not increase with fatigue, potentially even decreasing, suggesting that healthy subjects load limbs similarly as fatigue increases, exposing each to similar training stimuli.

Quantitative facial asymmetry: using three-dimensional photogrammetry to measure baseline facial surface symmetry.

PubMed

Taylor, Helena O; Morrison, Clinton S; Linden, Olivia; Phillips, Benjamin; Chang, Johnny; Byrne, Margaret E; Sullivan, Stephen R; Forrest, Christopher R

2014-01-01

Although symmetry is hailed as a fundamental goal of aesthetic and reconstructive surgery, our tools for measuring this outcome have been limited and subjective. With the advent of three-dimensional photogrammetry, surface geometry can be captured, manipulated, and measured quantitatively. Until now, few normative data existed with regard to facial surface symmetry. Here, we present a method for reproducibly calculating overall facial symmetry and present normative data on 100 subjects. We enrolled 100 volunteers who underwent three-dimensional photogrammetry of their faces in repose. We collected demographic data on age, sex, and race and subjectively scored facial symmetry. We calculated the root mean square deviation (RMSD) between the native and reflected faces, reflecting about a plane of maximum symmetry. We analyzed the interobserver reliability of the subjective assessment of facial asymmetry and the quantitative measurements and compared the subjective and objective values. We also classified areas of greatest asymmetry as localized to the upper, middle, or lower facial thirds. This cluster of normative data was compared with a group of patients with subtle but increasing amounts of facial asymmetry. We imaged 100 subjects by three-dimensional photogrammetry. There was a poor interobserver correlation between subjective assessments of asymmetry (r = 0.56). There was a high interobserver reliability for quantitative measurements of facial symmetry RMSD calculations (r = 0.91-0.95). The mean RMSD for this normative population was found to be 0.80 ± 0.24 mm. Areas of greatest asymmetry were distributed as follows: 10% upper facial third, 49% central facial third, and 41% lower facial third. Precise measurement permitted discrimination of subtle facial asymmetry within this normative group and distinguished norms from patients with subtle facial asymmetry, with placement of RMSDs along an asymmetry ruler. Facial surface symmetry, which is poorly assessed

Intrinsic Dawn-Dusk Asymmetry of Magnetotail Thin Current Sheet

NASA Astrophysics Data System (ADS)

Lu, S.; Pritchett, P. L.; Angelopoulos, V.; Artemyev, A.

2017-12-01

Magnetic reconnection and its related phenomena (flux ropes, dipolarization fronts, bursty bulk flows, particle injections, etc.) occur more frequently on the duskside in the Earth's magnetotail. Magnetohydrodynamic simulations attributed the asymmetry to the nonuniform ionospheric conductance through global scale magnetosphere-ionosphere interaction. Hybrid simulations, on the other hand, found an alternative responsible mechanism: the Hall effect in the magnetotail thin current sheet, but left an open question: What is the physical origin of the asymmetric Hall effect? The answer could be the temperature difference on the two sides and/or the dawn-dusk transportation of magnetic flux and plasmas. In this work, we use 3-D particle-in-cell simulations to further explore the magnetotail dawn-dusk asymmetry. The magnetotail equilibrium contains a dipole magnetic field and a current sheet region. The simulation is driven by a symmetric and localized (in the y direction) high-latitude electric field, under which the current sheet thins with a decrease of Bz. During the same time, a dawn-dusk asymmetry is formed intrinsically in the thin current sheet, with a smaller Bz, a stronger Hall effect (indicated by the Hall electric field Ez), and a stronger cross-tail current jy on the duskside. The deep origin of the asymmetry is also shown to be dominated by the dawnward E×B drift of magnetic flux and plasmas. A direct consequence of this intrinsic dawn-dusk asymmetry is that it favors magnetotail reconnection and related phenomena to preferentially occur on the duskside.

Frontal Brain Asymmetry and Willingness to Pay

PubMed Central

Ramsøy, Thomas Z.; Skov, Martin; Christensen, Maiken K.; Stahlhut, Carsten

2018-01-01

Consumers frequently make decisions about how much they are willing to pay (WTP) for specific products and services, but little is known about the neural mechanisms underlying such calculations. In this study, we were interested in testing whether specific brain activation—the asymmetry in engagement of the prefrontal cortex—would be related to consumer choice. Subjects saw products and subsequently decided how much they were willing to pay for each product, while undergoing neuroimaging using electroencephalography. Our results demonstrate that prefrontal asymmetry in the gamma frequency band, and a trend in the beta frequency band that was recorded during product viewing was significantly related to subsequent WTP responses. Frontal asymmetry in the alpha band was not related to WTP decisions. Besides suggesting separate neuropsychological mechanisms of consumer choice, we find that one specific measure—the prefrontal gamma asymmetry—was most strongly related to WTP responses, and was most coupled to the actual decision phase. These findings are discussed in light of the psychology of WTP calculations, and in relation to the recent emergence of consumer neuroscience and neuromarketing. PMID:29662432

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; Abazov, V. M.; Abbott, B.

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy ofmore » $$\\sqrt s =1.96$$ TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is $$A_{\\mathrm{FB}}^{t\\bar{t}} = 0.128 \\pm 0.025$$. As a result, the combined inclusive and differential asymmetries are consistent with recent standard model predictions.« less

Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

DOE PAGES

Aaltonen, T.; Abazov, V. M.; Abbott, B.; ...

2018-01-24

The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy ofmore » $$\\sqrt s =1.96$$ TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is $$A_{\\mathrm{FB}}^{t\\bar{t}} = 0.128 \\pm 0.025$$. As a result, the combined inclusive and differential asymmetries are consistent with recent standard model predictions.« less

Information Asymmetries as Trade Barriers: ISO 9000 Increases International Commerce

ERIC Educational Resources Information Center

Potoski, Matthew; Prakash, Aseem

2009-01-01

Spatial, cultural, and linguistic barriers create information asymmetries between buyers and sellers that impede international trade. The International Organization for Standardization's ISO 9000 program is designed to reduce these information asymmetries by providing assurance about the product quality of firms that receive its certification.…

Asymmetries of Knowledge and Epistemic Change in Social Gaming Interaction

ERIC Educational Resources Information Center

Piirainen-Marsh, Arja; Tainio, Liisa

2014-01-01

While a growing number of studies investigate the role of knowledge and interactional management of knowledge asymmetries in conversation analysis, the epistemic organization of multilingual and second language interactions is still largely unexplored. This article addresses this issue by investigating how knowledge asymmetries and changing…

Cerebral monitoring during cardiopulmonary bypass in children.

PubMed

Kern, F H; Schell, R M; Greeley, W J

1993-07-01

Although cerebral monitoring during CPB remains primarily investigational, recent data support its clinical utility. In particular, it is cerebral metabolic monitoring that provides meaningful information in terms of preparing the brain for dhCPB and dhCA. Cerebral blood flow or cerebral blood flow velocity monitoring is less beneficial due to the presence of luxuriant cerebral blood flow at deep hypothermic temperatures. Conventional temperature monitoring can be improved upon by adding jugular venous oxygen saturation monitoring to satisfy the primary goal of cerebral protection--uniform cerebral cooling and metabolic suppression. Although online measures of cerebral cellular metabolism are not widely available, early experience with near infrared technology suggests that it is a feasible and reliable monitor of cerebral metabolic activity and is likely to represent an important noninvasive continuous monitor in the near future. CMRO2 recovery data have suggested that cerebral metabolic suppression is more severe the longer the period of dhCA. Cerebral protection strategies, such as intermittent cerebral perfusion have demonstrated less metabolic suppression of dhCA in animal models and are currently undergoing clinical evaluation in our institution. Finally, the postoperative period remains a high-risk period for neurologic injury because temperatures are normothermic, cardiac output is reduced, cerebral autoregulation is impaired, and management strategies, such as hyperventilation, are commonly used to increase pulmonary blood flow with little knowledge on its effects on cerebral perfusion.

Asymmetric pelvic and hip rotation in children with bilateral cerebral palsy: uni- or bilateral femoral derotation osteotomy?

PubMed

Niklasch, M; Döderlein, L; Klotz, M C; Braatz, F; Wolf, S I; Dreher, T

2015-02-01

Internal rotation gait is common among children with bilateral cerebral palsy. However, despite bilaterally increased femoral anteversion asymmetric internal rotation gait is often found. Femoral derotation osteotomy (FDO) is commonly performed bilaterally. Variable functional outcomes are reported especially in cases with mild internal hip rotation during gait and abnormal preoperative pelvic rotation. A major question is if a unilateral treatment of the more involved side in asymmetric cases leads to a comparable or even superior outcome. One hundred and nine children with spastic bilateral CP treated with FDO with pre- and 1-year postoperative 3D gait analysis were retrospectively collected. The asymmetry was calculated from the preoperative difference between both limbs in hip rotation obtained by 3D gait analysis. Twenty-eight children with asymmetry larger than 20° were selected and classified into two groups, according to whether they obtained a unilateral or bilateral FDO. Preoperative clinical examination and pre- and postoperative hip and pelvic rotation in gait analysis on the more and the less involved side did not differ significantly between both groups. Interestingly, in both groups, hip rotation did not change significantly in less-involved limbs, although intraoperative derotation averaged 25°. After unilateral FDO a significant change in pelvic rotation resulted, whereas this was not found after bilateral FDO. The results of this study suggest that unilateral FDO in children with asymmetric internal rotation gait leads to a comparable functional outcome compared to bilateral treatment. Furthermore, it was shown for the first time that considering the asymmetry has a positive effect on pelvic rotation. Copyright © 2015 Elsevier B.V. All rights reserved.

A newly identified left-right asymmetry in larval sea urchins.

PubMed

Hodin, Jason; Lutek, Keegan; Heyland, Andreas

2016-08-01

Directional asymmetry (DA) in body form is a widespread phenomenon in animals and plants alike, and a functional understanding of such asymmetries can offer insights into the ways in which ecology and development interface to drive evolution. Echinoids (sea urchins, sand dollars and their kin) with planktotrophic development have a bilaterally symmetrical feeding pluteus larva that undergoes a dramatic metamorphosis into a pentameral juvenile that enters the benthos at settlement. The earliest stage of this transformation involves a DA: a left-side invagination in mid-stage larvae leads to the formation of the oral field of the juvenile via a directionally asymmetric structure called the echinus rudiment. Here, we show for the first time in two echinoid species that there is a corresponding DA in the overall shape of the larva: late-stage plutei have consistently shorter arms specifically on the rudiment (left) side. We then demonstrate a mechanistic connection between the rudiment and arm length asymmetries by examining rare, anomalous purple urchin larvae that have rudiments on both the left and the right side. Our data suggest that this asymmetry is probably a broadly shared feature characterizing ontogeny in the class Echinoidea. We propose several functional hypotheses-including developmental constraints and water column stability-to account for this newly identified asymmetry.

A newly identified left–right asymmetry in larval sea urchins

PubMed Central

Hodin, Jason; Lutek, Keegan

2016-01-01

Directional asymmetry (DA) in body form is a widespread phenomenon in animals and plants alike, and a functional understanding of such asymmetries can offer insights into the ways in which ecology and development interface to drive evolution. Echinoids (sea urchins, sand dollars and their kin) with planktotrophic development have a bilaterally symmetrical feeding pluteus larva that undergoes a dramatic metamorphosis into a pentameral juvenile that enters the benthos at settlement. The earliest stage of this transformation involves a DA: a left-side invagination in mid-stage larvae leads to the formation of the oral field of the juvenile via a directionally asymmetric structure called the echinus rudiment. Here, we show for the first time in two echinoid species that there is a corresponding DA in the overall shape of the larva: late-stage plutei have consistently shorter arms specifically on the rudiment (left) side. We then demonstrate a mechanistic connection between the rudiment and arm length asymmetries by examining rare, anomalous purple urchin larvae that have rudiments on both the left and the right side. Our data suggest that this asymmetry is probably a broadly shared feature characterizing ontogeny in the class Echinoidea. We propose several functional hypotheses—including developmental constraints and water column stability—to account for this newly identified asymmetry. PMID:27853591

Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex.

PubMed

Guadalupe, Tulio; Mathias, Samuel R; vanErp, Theo G M; Whelan, Christopher D; Zwiers, Marcel P; Abe, Yoshinari; Abramovic, Lucija; Agartz, Ingrid; Andreassen, Ole A; Arias-Vásquez, Alejandro; Aribisala, Benjamin S; Armstrong, Nicola J; Arolt, Volker; Artiges, Eric; Ayesa-Arriola, Rosa; Baboyan, Vatche G; Banaschewski, Tobias; Barker, Gareth; Bastin, Mark E; Baune, Bernhard T; Blangero, John; Bokde, Arun L W; Boedhoe, Premika S W; Bose, Anushree; Brem, Silvia; Brodaty, Henry; Bromberg, Uli; Brooks, Samantha; Büchel, Christian; Buitelaar, Jan; Calhoun, Vince D; Cannon, Dara M; Cattrell, Anna; Cheng, Yuqi; Conrod, Patricia J; Conzelmann, Annette; Corvin, Aiden; Crespo-Facorro, Benedicto; Crivello, Fabrice; Dannlowski, Udo; de Zubicaray, Greig I; de Zwarte, Sonja M C; Deary, Ian J; Desrivières, Sylvane; Doan, Nhat Trung; Donohoe, Gary; Dørum, Erlend S; Ehrlich, Stefan; Espeseth, Thomas; Fernández, Guillén; Flor, Herta; Fouche, Jean-Paul; Frouin, Vincent; Fukunaga, Masaki; Gallinat, Jürgen; Garavan, Hugh; Gill, Michael; Suarez, Andrea Gonzalez; Gowland, Penny; Grabe, Hans J; Grotegerd, Dominik; Gruber, Oliver; Hagenaars, Saskia; Hashimoto, Ryota; Hauser, Tobias U; Heinz, Andreas; Hibar, Derrek P; Hoekstra, Pieter J; Hoogman, Martine; Howells, Fleur M; Hu, Hao; Hulshoff Pol, Hilleke E; Huyser, Chaim; Ittermann, Bernd; Jahanshad, Neda; Jönsson, Erik G; Jurk, Sarah; Kahn, Rene S; Kelly, Sinead; Kraemer, Bernd; Kugel, Harald; Kwon, Jun Soo; Lemaitre, Herve; Lesch, Klaus-Peter; Lochner, Christine; Luciano, Michelle; Marquand, Andre F; Martin, Nicholas G; Martínez-Zalacaín, Ignacio; Martinot, Jean-Luc; Mataix-Cols, David; Mather, Karen; McDonald, Colm; McMahon, Katie L; Medland, Sarah E; Menchón, José M; Morris, Derek W; Mothersill, Omar; Maniega, Susana Munoz; Mwangi, Benson; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswaamy, Janardhanan C; Nees, Frauke; Nordvik, Jan E; Onnink, A Marten H; Opel, Nils; Ophoff, Roel; Paillère Martinot, Marie-Laure; Papadopoulos Orfanos, Dimitri; Pauli, Paul; Paus, Tomáš; Poustka, Luise; Reddy, Janardhan Yc; Renteria, Miguel E; Roiz-Santiáñez, Roberto; Roos, Annerine; Royle, Natalie A; Sachdev, Perminder; Sánchez-Juan, Pascual; Schmaal, Lianne; Schumann, Gunter; Shumskaya, Elena; Smolka, Michael N; Soares, Jair C; Soriano-Mas, Carles; Stein, Dan J; Strike, Lachlan T; Toro, Roberto; Turner, Jessica A; Tzourio-Mazoyer, Nathalie; Uhlmann, Anne; Hernández, Maria Valdés; van den Heuvel, Odile A; van der Meer, Dennis; van Haren, Neeltje E M; Veltman, Dick J; Venkatasubramanian, Ganesan; Vetter, Nora C; Vuletic, Daniella; Walitza, Susanne; Walter, Henrik; Walton, Esther; Wang, Zhen; Wardlaw, Joanna; Wen, Wei; Westlye, Lars T; Whelan, Robert; Wittfeld, Katharina; Wolfers, Thomas; Wright, Margaret J; Xu, Jian; Xu, Xiufeng; Yun, Je-Yeon; Zhao, JingJing; Franke, Barbara; Thompson, Paul M; Glahn, David C; Mazoyer, Bernard; Fisher, Simon E; Francks, Clyde

2017-10-01

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders.

UV Observations of Hemispheric Asymmetry

NASA Astrophysics Data System (ADS)

Schaefer, R. K.; Paxton, L. J.; Wolven, B. C.; Zhang, Y.; Romeo, G.

2015-12-01

Asymmetry in the auroral patterns can be an important diagnostic for understanding the dynamics of solar wind interaction with the magnetosphere-ionosphere-thermosphere system (e.g., Newel and Meng, 1998; Fillingrim et al., 2005). Molecular nitrogen emission in the UV Lyman-Birge-Hopfield bands can be used to determine energy flux and electron mean energy (Sotirelis, et al, 2013) and thereby Hall and Pederson integrated conductances (Gjerloev, et al., 2014). UV imagery provided by the 4 SSUSI instruments on the Defense Meteorological Satellite Program (DMSP) F16-F19 spacecraft provide two dimensional maps of this emission at different local times. Often there are near simultaneous observations of both poles by some combination of the satellites. (see figure 1) The SSUSI auroral data products are well suited to this study, as they have the following features.: - dayglow has been subtracted on dayside aurora - electron energy flux and mean energy are pre-calculated - individual arcs have been identified through image processing. In order to intercompare data from multiple satellites, we must first ensure that the instrument calibrations are consistent. In this work we show that the instruments are consistently calibrated, and that results generated from the SSUSI data products can be trusted. Several examples of storm time asymmetries captured by the SSUSI instruments will be discussed. Fillingim, M. O., G. K. Parks, H. U. Frey, T. J. Immel, and S. B. Mende (2005), Hemispheric asymmetry of the afternoon electron aurora, Geophys. Res. Lett., 32, L03113, doi:10.1029/2004GL021635. Gjerloev, J., Schaefer, R., Paxton, L, and Zhang, Y. (2014), A comprehensive empirical model of the ionospheric conductivity derived from SSUSI/GUVI, SuperMAG and SuperDARN data, SM51G-4339, Fall 2014 AGU meeting, San Francisco. Newell, P. T., and C.-I. Meng (1988), Hemispherical asymmetry in cusp precipitation near solstices, J. Geophys. Res., 93(A4), 2643-2648, doi:10.1029/JA093iA04p02643

Interhemispheric Asymmetry in the Mesosphere and Lower Thermosphere Observed by SABER/TIMED

NASA Astrophysics Data System (ADS)

Yee, J. H.

2017-12-01

In this paper we analyze nearly 15 years of satellite observations of temperature, airglow, and composition in the Mesosphere and Lower Thermosphere (MLT) to quantify their interhemispheric asymmetries ao one can provide quantitative links between observed asymmetries and the spatial and temporal variations of the gravity wave activity. Two processes are believed to be responsible for observed interhemispheric differences in the MLT. The first is the direct radiation effect from the eccentricity of the Earth orbit amd the other is the difference in gravity wave source distribution and filtering due to asymmetries in mean winds of the lower atmosphere. Both processes have been theoretically investigated to explain the observed asymmetry in some of the atmospheric parameters, but not self-consistently in all observed parameters together. In this paper we will show the asymmetry in the time-varying zonal-mean latitudinal structures of temperature, airglow emission rate, and composition observed by TIMED/SABER. We will quantify their interhemispheric asymmetries for different seasons under different solar activity conditions. In addition, temperature measurements will also be used to obtain temporal and spatial morphology of gravity wave potential energies. We will interpret the asymmetry in the observed fields and examine qualitatively their consistency with the two responsible processes, especially the one due to gravity wave filtering process. Our goal is to introduce and to share the spatial and temporal morphologies of all the observed fields to the modeling community so, together self-consistently, they be can be used to gain physical insights into the relative importance of various drivers responsible for the observed asymmetry, especially the role of gravity wave induced eddy drag and mixing, a critical, but least quantitatively understood process.

North–South Asymmetry of the Rotation of the Solar Magnetic Field

NASA Astrophysics Data System (ADS)

Xie, Jinglan; Shi, Xiangjun; Qu, Zhining

2018-03-01

Using the rotation rates of the solar magnetic field during solar cycles 21 to 23 obtained by Chu et al. by analyzing the synoptic magnetic maps produced by the NSO/Kitt Peak and SOHO/MDI during the years 1975 to 2008, the temporal variation of the equatorial rotation rate (A) and the latitude gradient of rotation (B) in the northern and southern hemispheres are studied separately. The results indicate that the rotation is more differential (about 4.3%) in the southern hemisphere in the considered time frame. It is found that the north–south asymmetry of A and the asymmetry of B show increasing trends in the considered time frame, while the north–south asymmetry of the solar activity shows a decreasing trend. There exists a significant negative correlation (at 95% confidence level) between the asymmetry of B and the asymmetry of the solar activity, and this may be due to stronger magnetic activity in a certain hemisphere that may suppress the differential rotation to some extent. The periodicities in the variation of A and B are also studied, and periods of about 5.0 and 10.5 yr (5.5 and 10.4 yr) can be found for the variation of the northern (southern) hemisphere B. Moreover, the north–south asymmetry of A and the asymmetry of B have similar periods of about 2.6–2.7 and 5.2–5.3 yr. Further, cross-correlation analysis indicates that there exists a phase difference (about eight months) between the northern and southern hemisphere B, and this means that the northern hemisphere B generally leads by about eight months.

Complementary and alternative medicine for multiple sclerosis.

PubMed

Schwarz, S; Knorr, C; Geiger, H; Flachenecker, P

2008-09-01

We analyzed characteristics, motivation, and effectiveness of complementary and alternative medicine in a large sample of people with multiple sclerosis. A 53-item survey was mailed to the members of the German Multiple Sclerosis Society, chapter of Baden-Wuerttemberg. Surveys of 1573 patients (48.5 +/- 11.7 years, 74% women, duration of illness 18.1 +/- 10.5 years) were analyzed. In comparison with conventional medicine, more patients displayed a positive attitude toward complementary and alternative medicine (44% vs 38%, P < 0.05), with 70% reporting lifetime use of at least one method. Among a wide variety of complementary and alternative medicine, diet modification (41%), Omega-3 fatty acids (37%), removal of amalgam fillings (28%), vitamins E (28%), B (36%), and C (28%), homeopathy (26%), and selenium (24%) were cited most frequently. Most respondents (69%) were satisfied with the effects of complementary and alternative medicine. Use of complementary and alternative medicine was associated with religiosity, functional independence, female sex, white-collar job, and higher education (P < 0.05). Compared with conventional therapies, complementary and alternative medicine rarely showed unwanted side effects (9% vs 59%, P < 0.00001). A total of 52% stated that the initial consultation with their physician lasted less than 15 min. To conclude, main reasons for the use of complementary and alternative medicine include the high rate of side effects and low levels of satisfaction with conventional treatments and brief patients/physicians contacts.

Sex differences in structural brain asymmetry predict overt aggression in early adolescents.

PubMed

Visser, Troy A W; Ohan, Jeneva L; Whittle, Sarah; Yücel, Murat; Simmons, Julian G; Allen, Nicholas B

2014-04-01

The devastating social, emotional and economic consequences of human aggression are laid bare nightly on newscasts around the world. Aggression is principally mediated by neural circuitry comprising multiple areas of the prefrontal cortex and limbic system, including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), amygdala and hippocampus. A striking characteristic of these regions is their structural asymmetry about the midline (i.e. left vs right hemisphere). Variations in these asymmetries have been linked to clinical disorders characterized by aggression and the rate of aggressive behavior in psychiatric patients. Here, we show for the first time that structural asymmetries in prefrontal cortical areas are also linked to aggression in a normal population of early adolescents. Our findings indicate a relationship between parent reports of aggressive behavior in adolescents and structural asymmetries in the limbic and paralimbic ACC and OFC, and moreover, that this relationship varies by sex. Furthermore, while there was no relationship between aggression and structural asymmetries in the amygdala or hippocampus, hippocampal volumes did predict aggression in females. Taken together, the results suggest that structural asymmetries in the prefrontal cortex may influence human aggression, and that the anatomical basis of aggression varies substantially by sex.

Cerebral Blood Flow and Cerebral Edema in Rats With Diabetic Ketoacidosis

PubMed Central

Yuen, Natalie; Anderson, Steven E.; Glaser, Nicole; Tancredi, Daniel J.; O'Donnell, Martha E.

2008-01-01

OBJECTIVE— Cerebral edema (CE) is a potentially life-threatening complication of diabetic ketoacidosis (DKA) in children. Osmotic fluctuations during DKA treatment have been considered responsible, but recent data instead suggest that cerebral hypoperfusion may be involved and that activation of cerebral ion transporters may occur. Diminished cerebral blood flow (CBF) during DKA, however, has not been previously demonstrated. We investigated CBF and edema formation in a rat model of DKA and determined the effects of bumetanide, an inhibitor of Na-K-Cl cotransport. RESEARCH DESIGN AND METHODS— Juvenile rats with streptozotocin-induced DKA were treated with intravenous saline and insulin, similar to human treatment protocols. CBF was determined by magnetic resonance (MR) perfusion–weighted imaging before and during treatment, and CE was assessed by determining apparent diffusion coefficients (ADCs) using MR diffusion–weighted imaging. RESULTS— CBF was significantly reduced in DKA and was responsive to alterations in pCO2. ADC values were reduced, consistent with cell swelling. The reduction in ADCs correlated with dehydration, as reflected in blood urea nitrogen concentrations. Bumetanide caused a rapid rise in ADCs of DKA rats without significantly changing CBF, while saline/insulin caused a rapid rise in CBF and a gradual rise in ADCs. DKA rats treated with bumetanide plus saline/insulin showed a trend toward more rapid rise in cortical ADCs and a larger rise in striatal CBF than those observed with saline/insulin alone. CONCLUSIONS— These data demonstrate that CE in DKA is accompanied by cerebral hypoperfusion before treatment and suggest that blocking Na-K-Cl cotransport may reduce cerebral cell swelling. PMID:18633109

Revisiting cerebral thromboangiitis obliterans.

PubMed

Hurelbrink, Carrie B; Barnett, Yael; Buckland, Michael E; Wilkinson, Mark; Leicester, Jon; Anderson, Craig; Brennan, Jeffrey; Barnett, Michael

2012-06-15

We describe a 56-year-old patient with progressive cognitive decline in the context of heavy tobacco use and migraine, and imaging evidence of an occlusive terminal cerebral vasculopathy. The results of brain biopsy recapitulated the pathological features described by Lindenberg and Spatz in their classic 1939 treatise on cerebral thromboangiitis obliterans, or cerebral Buerger's disease. Although the condition is associated with heavy smoking, the identification of a hypercoagulable state in our patient suggests a multifactorial pathogenesis. The diagnosis of cerebral thromboangiitis obliterans in life is facilitated by modern neuroimaging and should prompt immediate cessation of smoking and a search for an underlying prothrombotic tendency. Copyright © 2012 Elsevier B.V. All rights reserved.

A new genus of long-legged flies displaying remarkable wing directional asymmetry

Treesearch

Justin B. Runyon; Richard L. Hurley

2004-01-01

A previously unknown group of flies is described whose males exhibit directional asymmetry, in that the left wing is larger than, and of a different shape from, the right wing. To our knowledge, wing asymmetry of this degree has not previously been reported in an animal capable of flight. Such consistent asymmetry must result from a left­right axis during development...

[Epidemiological study of dental and facial asymmetries in a sample of preschool subjects].

PubMed

Vitale, Marina Consuelo; Barbieri, Federica; Ricotta, Riccardo; Arpesella, Marisa; Emanuelli, Maria Teresa

2015-01-01

to identify the typologies of facial and dental asymmetries in a sample of children aged between 3 and 6 years and to correlate these asymmetries with possible morphological and functional situations. cross-sectional observational study. sample of 95 subjects aged between 3 and 6 years. Clinical data were collected in 10 sessions conducted during school hours in April 2013 by a doctor of Dentistry at two preschools in the city of Sanremo (Liguria Region, Northern Italy) and a kindergarten in the city of Pavia (Lombardy Region, Northern Italy). To collect the data, a weighted clinical questionnaire was used. presence and type of bad habit, type of breathing, presence and type of facial asymmetry, dental formula, presence of diastema, presence and type of occlusal asymmetries, presence and type of dental malocclusions. analysed sample consisted of 53.7% (51/95) of males and 46.3 % (44/95) females; the mean age was 4.3 ± 0.9 years. Most frequent facial asymmetry is orbits asymmetry (35%, 33/95); dental malocclusions are detected in 70%(67/95) of cases. High percentage of subjects (69.5%, 66/95) presents displacement between superior dental midline (SDM) and inferior dental midline (IDM). Several statistically significant associations are observed: in particular, asymmetry of molar ratios is linked to asymmetry of the cheekbones and displacement of the SDM; facial midline has statistical association with asymmetry of the cheekbones (p <0.001). the results of this study agree with scientific literature, in particular as regards the prevalence of compromising habits observed and the close correlation between: the presence of dental malocclusions and the presence of compromising habits, the presence of dental malocclusions and the presence of oral breathing.

Main effect and interactions of brain regions and gender in the calculation of volumetric asymmetry indices in healthy human brains: ANCOVA analyses of in vivo 3T MRI data.

PubMed

Roldan-Valadez, Ernesto; Rios, Camilo; Suarez-May, Marcela A; Favila, Rafel; Aguilar-Castañeda, Erika

2013-12-01

Macroanatomical right-left hemispheric differences in the brain are termed asymmetries, although there is no clear information on the global influence of gender and brain-regions. The aim of this study was to evaluate the main effects and interactions of these variables on the measurement of volumetric asymmetry indices (VAIs). Forty-seven healthy young-adult volunteers (23 males, 24 females) agreed to undergo brain magnetic resonance imaging in a 3T scanner. Image post processing using voxel-based volumetry allowed the calculation of 54 VAIs from the frontal, temporal, parietal and occipital lobes, limbic system, basal ganglia, and cerebellum for each cerebral hemisphere. Multivariate ANCOVA analysis calculated the main effects and interactions on VAIs of gender and brain regions controlling the effect of age. The only significant finding was the main effect of brain regions (F (6, 9373.605) 44.369, P < .001; partial η2 = .101, and power of 1.0), with no significant interaction between gender and brain regions (F (6, 50.517) .239, P = .964). Volumetric asymmetries are present across all brain regions, with larger values found in the limbic system and parietal lobe. The absence of a significant influence of gender and age in the evaluation of the numerous measurements generated by multivariate analyses in this study should not discourage researchers to report and interpret similar results, as this topic still deserves further assessment. Copyright © 2013 Wiley Periodicals, Inc.

Frontal brain asymmetry in adult attention-deficit/hyperactivity disorder (ADHD): extending the motivational dysfunction hypothesis.

PubMed

Keune, Philipp M; Wiedemann, Eva; Schneidt, Alexander; Schönenberg, Michael

2015-04-01

Attention-deficit/hyperactivity disorder (ADHD) involves motivational dysfunction, characterized by excessive behavioral approach tendencies. Frontal brain asymmetry in the alpha band (8-13 Hz) in resting-state electroencephalogram (EEG) represents a neural correlate of global motivational tendencies, and abnormal asymmetry, indicating elevated approach motivation, was observed in pediatric and adult patients. To date, the relation between ADHD symptoms, depression and alpha asymmetry, its temporal metric properties and putative gender-specificity remain to be explored. Adult ADHD patients (n=52) participated in two resting-state EEG recordings, two weeks apart. Asymmetry measures were aggregated across recordings to increase trait specificity. Putative region-specific associations between asymmetry, ADHD symptoms and depression, its gender-specificity and test-retest reliability were examined. ADHD symptoms were associated with approach-related asymmetry (stronger relative right-frontal alpha power). Approach-related asymmetry was pronounced in females, and also associated with depression. The latter association was mediated by ADHD symptoms. Test-retest reliability was sufficient. The association between reliably assessable alpha asymmetry and ADHD symptoms supports the motivational dysfunction hypothesis. ADHD symptoms mediating an atypical association between asymmetry and depression may be attributed to depression arising secondary to ADHD. Gender-specific findings require replication. Frontal alpha asymmetry may represent a new reliable marker of ADHD symptoms. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

PET of serotonin 1A receptors and cerebral glucose metabolism for temporal lobectomy.

PubMed

Theodore, William H; Martinez, Ashley R; Khan, Omar I; Liew, Clarissa J; Auh, Sungyoung; Dustin, Irene M; Heiss, John; Sato, Susumu

2012-09-01

The objective of this study was to compare 5-hydroxytryptamine receptor 1A (5-HT(1A)) PET with cerebral metabolic rate of glucose (CMRglc) PET for temporal lobectomy planning. We estimated 5-HT(1A) receptor binding preoperatively with (18)F-trans-4-fluoro-N-2-[4-(2-methoxyphenyl) piperazin-1-yl]ethyl-N-(2-pyridyl) cyclohexane carboxamide ((18)F-FCWAY) PET and CMRglc measurement with (18)F-FDG in regions drawn on coregistered MRI after partial-volume correction in 41 patients who had anterior temporal lobectomy with at least a 1-y follow-up. Surgery was tailored to individual preresection evaluations and intraoperative electrocorticography. Mean regional asymmetry values and the number of regions with asymmetry exceeding 2 SDs in 16 healthy volunteers were compared between seizure-free and non-seizure-free patients. (18)F-FCWAY but not (18)F-FDG and MRI data were masked for surgical decisions and outcome assessment. Twenty-six of 41 (63%) patients seizure-free since surgery had significantly different mesial temporal asymmetries, compared with 15 non-seizure-free patients for both (18)F-FCWAY (F(1,39) = 5.87; P = 0.02) and (18)F-FDG PET (F(1,38) = 5.79; P = 0.021). The probability of being seizure-free was explained by both (18)F-FDG and (18)F-FCWAY PET, but not MRI, with a significant additional (18)F-FCWAY effect (chi(2)(2) = 9.8796; P = 0.0072) after the probability of being seizure-free was explained by (18)F-FDG. Although MRI alone was not predictive, any combination of 2 lateralizing imaging studies was highly predictive of seizure freedom. Our study provides class III evidence that both 5-HT(1A) receptor PET and CMRglc PET can contribute to temporal lobectomy planning. Additional studies should explore the potential for temporal lobectomy based on interictal electroencephalography and minimally invasive imaging studies.

Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

PubMed

Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

2012-08-01

To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

The EIT- and N- joint resonance lineshape asymmetry

NASA Astrophysics Data System (ADS)

Crescimanno, Michael; Hancox, Cindy; Hohensee, Michael; Phillips, David; Walsworth, Ron

2008-03-01

The solution of a quantum optics model for the joint EIT- and N- resonance explains the experimentally observed two-photon lineshape asymmetry as arising from interference and AC stark effects. This solution is evaluated for various light field intensities, detunings and couplings associated with experiments performed on the D1 and D2 transition of 87Rb. Because of its contribution to clock instability, lineshape asymmetry remains perhaps the main impediment to improving all-optical time standards based on the joint resonance.

An Azimuthal Asymmetry in the LkHα 330 Disk

NASA Astrophysics Data System (ADS)

Isella, Andrea; Pérez, Laura M.; Carpenter, John M.; Ricci, Luca; Andrews, Sean; Rosenfeld, Katherine

2013-09-01

Theory predicts that giant planets and low mass stellar companions shape circumstellar disks by opening annular gaps in the gas and dust spatial distribution. For more than a decade it has been debated whether this is the dominant process that leads to the formation of transitional disks. In this paper, we present millimeter-wave interferometric observations of the transitional disk around the young intermediate mass star LkHα 330. These observations reveal a lopsided ring in the 1.3 mm dust thermal emission characterized by a radius of about 100 AU and an azimuthal intensity variation of a factor of two. By comparing the observations with a Gaussian parametric model, we find that the observed asymmetry is consistent with a circular arc, that extends azimuthally by about 90° and emits about 1/3 of the total continuum flux at 1.3 mm. Hydrodynamic simulations show that this structure is similar to the azimuthal asymmetries in the disk surface density that might be produced by the dynamical interaction with unseen low mass companions orbiting within 70 AU from the central star. We argue that such asymmetries might lead to azimuthal variations in the millimeter-wave dust opacity and in the dust temperature, which will also affect the millimeter-wave continuum emission. Alternative explanations for the observed asymmetry that do not require the presence of companions cannot be ruled out with the existing data. Further observations of both the dust and molecular gas emission are required to derive firm conclusions on the origin of the asymmetry observed in the LkHα 330 disk.

Determining Complementary Properties with Quantum Clones.

PubMed

Thekkadath, G S; Saaltink, R Y; Giner, L; Lundeen, J S

2017-08-04

In a classical world, simultaneous measurements of complementary properties (e.g., position and momentum) give a system's state. In quantum mechanics, measurement-induced disturbance is largest for complementary properties and, hence, limits the precision with which such properties can be determined simultaneously. It is tempting to try to sidestep this disturbance by copying the system and measuring each complementary property on a separate copy. However, perfect copying is physically impossible in quantum mechanics. Here, we investigate using the closest quantum analog to this copying strategy, optimal cloning. The coherent portion of the generated clones' state corresponds to "twins" of the input system. Like perfect copies, both twins faithfully reproduce the properties of the input system. Unlike perfect copies, the twins are entangled. As such, a measurement on both twins is equivalent to a simultaneous measurement on the input system. For complementary observables, this joint measurement gives the system's state, just as in the classical case. We demonstrate this experimentally using polarized single photons.

Determining Complementary Properties with Quantum Clones

NASA Astrophysics Data System (ADS)

Thekkadath, G. S.; Saaltink, R. Y.; Giner, L.; Lundeen, J. S.

2017-08-01

In a classical world, simultaneous measurements of complementary properties (e.g., position and momentum) give a system's state. In quantum mechanics, measurement-induced disturbance is largest for complementary properties and, hence, limits the precision with which such properties can be determined simultaneously. It is tempting to try to sidestep this disturbance by copying the system and measuring each complementary property on a separate copy. However, perfect copying is physically impossible in quantum mechanics. Here, we investigate using the closest quantum analog to this copying strategy, optimal cloning. The coherent portion of the generated clones' state corresponds to "twins" of the input system. Like perfect copies, both twins faithfully reproduce the properties of the input system. Unlike perfect copies, the twins are entangled. As such, a measurement on both twins is equivalent to a simultaneous measurement on the input system. For complementary observables, this joint measurement gives the system's state, just as in the classical case. We demonstrate this experimentally using polarized single photons.

Complementary Feeding: Review of Recommendations, Feeding Practices, and Adequacy of Homemade Complementary Food Preparations in Developing Countries – Lessons from Ethiopia

PubMed Central

Abeshu, Motuma Adimasu; Lelisa, Azeb; Geleta, Bekesho

2016-01-01

Breastfeeding provides the ideal food during the first 6 months of life. Complementary feeding starts when breast milk is no longer sufficient by itself, where the target age is for 6–23 months. The gap between nutritional requirement and amount obtained from breast milk increases with age. For energy, 200, 300, and 550 kcal per day is expected to be covered by complementary foods at 6–8, 9–11, and 12–23 months, respectively. In addition, the complementary foods must provide relatively large proportions of micronutrients such as iron, zinc, phosphorus, magnesium, calcium, and vitamin B6. In several parts of the developing world, complementary feeding continues as a challenge to good nutrition in children. In Ethiopia, only 4.2% of breastfed children of 6–23 months of age have a minimum acceptable diet. The gaps are mostly attributed to either poor dietary quality or poor feeding practices, if not both. Commercial fortified foods are often beyond the reach of the poor. Thus, homemade complementary foods remain commonly used. Even when based on an improved recipe, however, unfortified plant-based complementary foods provide insufficient key micronutrients (especially, iron, zinc, and calcium) during the age of 6–23 months. Thus, this review assessed complementary feeding practice and recommendation and reviewed the level of adequacy of homemade complementary foods. PMID:27800479

Asymmetry in Food Handling Behavior of a Tree-Dwelling Rodent (Sciurus vulgaris)

PubMed Central

Polo-Cavia, Nuria; Vázquez, Zoraida; de Miguel, Francisco Javier

2015-01-01

Asymmetry in motor patterns is present in a wide variety of animals. Many lateralized behaviors seem to depend on brain asymmetry, as it is the case of different tasks associated to food handling by several bird and mammal species. Here, we analyzed asymmetry in handling behavior of pine cones by red squirrels (Sciurus vulgaris). Red squirrels devote most of their daily activity to feeding, thus this species constitutes an appropriate model for studying asymmetry in food processing. We aimed to explore 1) the potential lateralization in handling of pine cones by squirrels, 2) the dominant pattern for this behavior (left- vs. right-handed), and 3) whether this pattern varies among populations and depending on the pine tree species available. Results revealed that red squirrels handle pine cones in an asymmetrical way, and that direction of asymmetry varies among populations and seems to be determined more by local influences rather than by the pine tree species. PMID:25714614

Head, withers and pelvic movement asymmetry and their relative timing in trot in racing Thoroughbreds in training.

PubMed

Pfau, T; Noordwijk, K; Sepulveda Caviedes, M F; Persson-Sjodin, E; Barstow, A; Forbes, B; Rhodin, M

2018-01-01

Horses show compensatory head movement in hindlimb lameness and compensatory pelvis movement in forelimb lameness but little is known about the relationship of withers movement symmetry with head and pelvic asymmetry in horses with naturally occurring gait asymmetries. To document head, withers and pelvic movement asymmetry and timing differences in horses with naturally occurring gait asymmetries. Retrospective analysis of gait data. Head, withers and pelvic movement asymmetry and timing of displacement minima and maxima were quantified from inertial sensors in 163 Thoroughbreds during trot-ups on hard ground. Horses were divided into 4 subgroups using the direction of head and withers movement asymmetry. Scatter plots of head vs. pelvic movement asymmetry illustrated how the head-withers relationship distinguishes between contralateral and ipsilateral head-pelvic movement asymmetry. Independent t test or Mann-Whitney U test (P<0.05) compared pelvic movement asymmetry and timing differences between groups. The relationship between head and withers asymmetry (i.e. same sided or opposite sided asymmetry) predicts the relationship between head and pelvic asymmetry in 69-77% of horses. Pelvic movement symmetry was significantly different between horses with same sign vs. opposite sign of head-withers asymmetry (P<0.0001). Timing of the maximum head height reached after contralateral ('sound') stance was delayed compared to withers (P = 0.02) and pelvis (P = 0.04) in horses with contralateral head-withers asymmetry. The clinical lameness status of the horses was not investigated. In the Thoroughbreds with natural gait asymmetries investigated here, the direction of head vs. withers movement asymmetry identifies the majority of horses with ipsilateral and contralateral head and pelvic movement asymmetries. Withers movement should be further investigated for differentiating between forelimb and hindlimb lame horses. Horses with opposite sided head and withers

Neurally Derived Tissues in Xenopus laevis Embryos Exhibit a Consistent Bioelectrical Left-Right Asymmetry

PubMed Central

Pai, Vaibhav P.; Vandenberg, Laura N.; Blackiston, Douglas; Levin, Michael

2012-01-01

Consistent left-right asymmetry in organ morphogenesis is a fascinating aspect of bilaterian development. Although embryonic patterning of asymmetric viscera, heart, and brain is beginning to be understood, less is known about possible subtle asymmetries present in anatomically identical paired structures. We investigated two important developmental events: physiological controls of eye development and specification of neural crest derivatives, in Xenopus laevis embryos. We found that the striking hyperpolarization of transmembrane potential (V mem) demarcating eye induction usually occurs in the right eye field first. This asymmetry is randomized by perturbing visceral left-right patterning, suggesting that eye asymmetry is linked to mechanisms establishing primary laterality. Bilateral misexpression of a depolarizing channel mRNA affects primarily the right eye, revealing an additional functional asymmetry in the control of eye patterning by V mem. The ATP-sensitive K+ channel subunit transcript, SUR1, is asymmetrically expressed in the eye primordia, thus being a good candidate for the observed physiological asymmetries. Such subtle asymmetries are not only seen in the eye: consistent asymmetry was also observed in the migration of differentiated melanocytes on the left and right sides. These data suggest that even anatomically symmetrical structures may possess subtle but consistent laterality and interact with other developmental left-right patterning pathways. PMID:23346115

Neurally Derived Tissues in Xenopus laevis Embryos Exhibit a Consistent Bioelectrical Left-Right Asymmetry.

PubMed

Pai, Vaibhav P; Vandenberg, Laura N; Blackiston, Douglas; Levin, Michael

2012-01-01

Consistent left-right asymmetry in organ morphogenesis is a fascinating aspect of bilaterian development. Although embryonic patterning of asymmetric viscera, heart, and brain is beginning to be understood, less is known about possible subtle asymmetries present in anatomically identical paired structures. We investigated two important developmental events: physiological controls of eye development and specification of neural crest derivatives, in Xenopus laevis embryos. We found that the striking hyperpolarization of transmembrane potential (V(mem)) demarcating eye induction usually occurs in the right eye field first. This asymmetry is randomized by perturbing visceral left-right patterning, suggesting that eye asymmetry is linked to mechanisms establishing primary laterality. Bilateral misexpression of a depolarizing channel mRNA affects primarily the right eye, revealing an additional functional asymmetry in the control of eye patterning by V(mem). The ATP-sensitive K(+) channel subunit transcript, SUR1, is asymmetrically expressed in the eye primordia, thus being a good candidate for the observed physiological asymmetries. Such subtle asymmetries are not only seen in the eye: consistent asymmetry was also observed in the migration of differentiated melanocytes on the left and right sides. These data suggest that even anatomically symmetrical structures may possess subtle but consistent laterality and interact with other developmental left-right patterning pathways.

Temporal change of EIA asymmetry revealed by a beacon receiver network in Southeast Asia

NASA Astrophysics Data System (ADS)

Watthanasangmechai, Kornyanat; Yamamoto, Mamoru; Saito, Akinori; Maruyama, Takashi; Yokoyama, Tatsuhiro; Nishioka, Michi; Ishii, Mamoru

2015-05-01

To reveal the temporal change of the equatorial ionization anomaly (EIA) asymmetry, a multipoint satellite-ground beacon experiment was conducted along the meridional plane of the Thailand-Indonesia sector. The observation includes one station near the magnetic equator and four stations at off-equator latitudes. This is the first EIA asymmetry study with high spatial resolution using GNU Radio Beacon Receiver (GRBR) observations in Southeast Asia. GRBR-total electron contents (TECs) from 97 polar-orbit satellite passes in March 2012 were analyzed in this study. Successive passes captured rapid evolution of EIA asymmetry, especially during geomagnetic disturbances. The penetrating electric fields that occur during geomagnetic disturbed days are not the cause of the asymmetry. Instead, high background TEC associated with an intense electric field empowers the neutral wind to produce severe asymmetry of the EIA. Such rapid evolution of EIA asymmetry was not seen during nighttime, when meridional wind mainly controlled the asymmetric structures. Additional data are necessary to identify the source of the variations, i.e., atmospheric waves. Precisely capturing the locations of the crests and the evolution of the asymmetry enhances understanding of the temporal change of EIA asymmetry at the local scale and leads to a future local modeling for TEC prediction in Southeast Asia.

Socioeconomic Status Is Not Related with Facial Fluctuating Asymmetry: Evidence from Latin-American Populations

PubMed Central

Quinto-Sánchez, Mirsha; Cintas, Celia; Silva de Cerqueira, Caio Cesar; Ramallo, Virginia; Acuña-Alonzo, Victor; Adhikari, Kaustubh; Castillo, Lucía; Gomez-Valdés, Jorge; Everardo, Paola; De Avila, Francisco; Hünemeier, Tábita; Jaramillo, Claudia; Arias, Williams; Fuentes, Macarena; Gallo, Carla; Poletti, Giovani; Schuler-Faccini, Lavinia; Bortolini, Maria Cátira; Canizales-Quinteros, Samuel; Rothhammer, Francisco; Bedoya, Gabriel; Rosique, Javier; Ruiz-Linares, Andrés; González-José, Rolando

2017-01-01

The expression of facial asymmetries has been recurrently related with poverty and/or disadvantaged socioeconomic status. Departing from the developmental instability theory, previous approaches attempted to test the statistical relationship between the stress experienced by individuals grown in poor conditions and an increase in facial and corporal asymmetry. Here we aim to further evaluate such hypothesis on a large sample of admixed Latin Americans individuals by exploring if low socioeconomic status individuals tend to exhibit greater facial fluctuating asymmetry values. To do so, we implement Procrustes analysis of variance and Hierarchical Linear Modelling (HLM) to estimate potential associations between facial fluctuating asymmetry values and socioeconomic status. We report significant relationships between facial fluctuating asymmetry values and age, sex, and genetic ancestry, while socioeconomic status failed to exhibit any strong statistical relationship with facial asymmetry. These results are persistent after the effect of heterozygosity (a proxy for genetic ancestry) is controlled in the model. Our results indicate that, at least on the studied sample, there is no relationship between socioeconomic stress (as intended as low socioeconomic status) and facial asymmetries. PMID:28060876

Mitigating the impact of hohlraum asymmetries in National Ignition Facility implosions using capsule shims

DOE PAGES

Clark, D. S.; Weber, C. R.; Smalyuk, V. A.; ...

2016-07-22

Here, current indirect drive implosion experiments on the National Ignition Facility (NIF) are believed to be strongly impacted by long wavelength perturbations driven by asymmetries in the hohlraum x-ray flux. To address this perturbation source, active efforts are underway to develop modified hohlraum designs with reduced asymmetry imprint. An alternative strategy, however, is to modify the capsule design to be more resilient to a given amount of hohlraum asymmetry. In particular, the capsule may be deliberately misshaped, or “shimmed,” so as to counteract the expected asymmetries from the hohlraum. Here, the efficacy of capsule shimming to correct the asymmetries inmore » two recent NIF implosion experiments is assessed using two-dimensional radiation hydrodynamics simulations. Despite the highly time-dependent character of the asymmetries and the high convergence ratios of these implosions, simulations suggest that shims could be highly effective at counteracting current asymmetries and result in factors of a few enhancements in neutron yields. For higher compression designs, the yield improvement could be even greater.« less

Mitigating the impact of hohlraum asymmetries in National Ignition Facility implosions using capsule shims

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, D. S.; Weber, C. R.; Smalyuk, V. A.

2016-07-15

Current indirect drive implosion experiments on the National Ignition Facility (NIF) [Moses et al., Phys. Plasmas 16, 041006 (2009)] are believed to be strongly impacted by long wavelength perturbations driven by asymmetries in the hohlraum x-ray flux. To address this perturbation source, active efforts are underway to develop modified hohlraum designs with reduced asymmetry imprint. An alternative strategy, however, is to modify the capsule design to be more resilient to a given amount of hohlraum asymmetry. In particular, the capsule may be deliberately misshaped, or “shimmed,” so as to counteract the expected asymmetries from the hohlraum. Here, the efficacy ofmore » capsule shimming to correct the asymmetries in two recent NIF implosion experiments is assessed using two-dimensional radiation hydrodynamics simulations. Despite the highly time-dependent character of the asymmetries and the high convergence ratios of these implosions, simulations suggest that shims could be highly effective at counteracting current asymmetries and result in factors of a few enhancements in neutron yields. For higher compression designs, the yield improvement could be even greater.« less

Socioeconomic Status Is Not Related with Facial Fluctuating Asymmetry: Evidence from Latin-American Populations.

PubMed

Quinto-Sánchez, Mirsha; Cintas, Celia; Silva de Cerqueira, Caio Cesar; Ramallo, Virginia; Acuña-Alonzo, Victor; Adhikari, Kaustubh; Castillo, Lucía; Gomez-Valdés, Jorge; Everardo, Paola; De Avila, Francisco; Hünemeier, Tábita; Jaramillo, Claudia; Arias, Williams; Fuentes, Macarena; Gallo, Carla; Poletti, Giovani; Schuler-Faccini, Lavinia; Bortolini, Maria Cátira; Canizales-Quinteros, Samuel; Rothhammer, Francisco; Bedoya, Gabriel; Rosique, Javier; Ruiz-Linares, Andrés; González-José, Rolando

2017-01-01

The expression of facial asymmetries has been recurrently related with poverty and/or disadvantaged socioeconomic status. Departing from the developmental instability theory, previous approaches attempted to test the statistical relationship between the stress experienced by individuals grown in poor conditions and an increase in facial and corporal asymmetry. Here we aim to further evaluate such hypothesis on a large sample of admixed Latin Americans individuals by exploring if low socioeconomic status individuals tend to exhibit greater facial fluctuating asymmetry values. To do so, we implement Procrustes analysis of variance and Hierarchical Linear Modelling (HLM) to estimate potential associations between facial fluctuating asymmetry values and socioeconomic status. We report significant relationships between facial fluctuating asymmetry values and age, sex, and genetic ancestry, while socioeconomic status failed to exhibit any strong statistical relationship with facial asymmetry. These results are persistent after the effect of heterozygosity (a proxy for genetic ancestry) is controlled in the model. Our results indicate that, at least on the studied sample, there is no relationship between socioeconomic stress (as intended as low socioeconomic status) and facial asymmetries.

Salient features of the ciliated organ of asymmetry

PubMed Central

Amack, Jeffrey D.

2014-01-01

Many internal organs develop distinct left and right sides that are essential for their functions. In several vertebrate embryos, motile cilia generate an asymmetric fluid flow that plays an important role in establishing left-right (LR) signaling cascades. These ‘LR cilia’ are found in the ventral node and posterior notochordal plate in mammals, the gastrocoel roof plate in amphibians and Kupffer’s vesicle in teleost fish. I consider these transient ciliated structures as the ‘organ of asymmetry’ that directs LR patterning of the developing embryo. Variations in size and morphology of the organ of asymmetry in different vertebrate species have raised questions regarding the fundamental features that are required for LR determination. Here, I review current models for how LR asymmetry is established in vertebrates, discuss the cellular architecture of the ciliated organ of asymmetry and then propose key features of this organ that are critical for orienting the LR body axis. PMID:24481178

Load Asymmetry Observed During Orion Main Parachute Inflation

NASA Technical Reports Server (NTRS)

Morris, Aaron L.; Taylor, Thomas; Olson, Leah

2011-01-01

The Crew Exploration Vehicle Parachute Assembly System (CPAS) has flight tested the first two generations of the Orion parachute program. Three of the second generation tests instrumented the dispersion bridles of the Main parachute with a Tension Measuring System. The goal of this load measurement was to better understand load asymmetry during the inflation process of a cluster of Main parachutes. The CPAS Main parachutes exhibit inflations that are much less symmetric than current parachute literature and design guides would indicate. This paper will examine loads data gathered on three cluster tests, quantify the degree of asymmetry observed, and contrast the results with published design guides. Additionally, the measured loads data will be correlated with videos of the parachute inflation to make inferences about the shape of the parachute and the relative load asymmetry. The goal of this inquiry and test program is to open a dialogue regarding asymmetrical parachute inflation load factors.

Reduction of Helicity-Dependent Instrumental Laser Intensity Asymmetries

NASA Astrophysics Data System (ADS)

Burtwistle, Samantha; Dreiling, Joan; Gay, Timothy

2014-05-01

We present a new optical system that greatly reduces helicity-dependent instrumental intensity asymmetries. The optical setup is similar to that described in Fabrikant et al., where two beams with orthogonal linear polarizations are sent through a chopper, allowing only one beam to pass through the optical system at a time. The two temporally-separated beams are then spatially recombined. We now use a system, with a second active polarization changing element, that is analogous to that described in Gay and Dunning, which compensates for false asymmetries in Mott polarimetry. In our setup, the orthogonal linear polarizations are now circularly polarized by a Pockels cell switching between a retardance of + λ /4 and - λ/4 at the same frequency as the chopper, but with a 90-degree phase shift. Using this method, we have been able to control the standard deviation of the mean of our asymmetries, as measured by a photodiode with lock-in signal processing, to 3*10-8.

Assisting Hand Assessment and Children's Hand-Use Experience Questionnaire -Observed Versus Perceived Bimanual Performance in Children with Unilateral Cerebral Palsy.

PubMed

Ryll, Ulrike C; Bastiaenen, Carolien H G; Eliasson, Ann-Christin

2017-05-01

To explore the differences, relationship, and extent of agreement between the Assisting Hand Assessment (AHA), measuring observed ability to perform bimanual tasks, and the Children's Hand-Use Experience Questionnaire (CHEQ), assessing experienced bimanual performance. This study investigates a convenience sample of 34 children (16 girls) with unilateral cerebral palsy aged 6-18 years (mean 12.1, SD 3.9) in a cross-sectional design. The AHA and CHEQ subscales share 8-25% of their variance (R 2 ). Bland-Altman plots for AHA and all three CHEQ subscales indicate good average agreement, with a mean difference approaching zero but large 95% confidence intervals. Limits of agreement were extremely wide, indicating considerable disagreement between AHA and CHEQ subscales. AHA and CHEQ seem to measure different though somewhat related constructs of bimanual performance. Results of this investigation reinforce the recommendation to use both instruments to obtain complementary information about bimanual performance including observed and perceived performance of children with unilateral cerebral palsy.

Sodium transport through the cerebral sodium-glucose transporter exacerbates neuron damage during cerebral ischaemia.

PubMed

Yamazaki, Yui; Harada, Shinichi; Wada, Tetsuyuki; Yoshida, Shigeru; Tokuyama, Shogo

2016-07-01

We recently demonstrated that the cerebral sodium-glucose transporter (SGLT) is involved in postischaemic hyperglycaemia-induced exacerbation of cerebral ischaemia. However, the associated SGLT-mediated mechanisms remain unclear. Thus, we examined the involvement of cerebral SGLT-induced excessive sodium ion influx in the development of cerebral ischaemic neuronal damage. [Na+]i was estimated according to sodium-binding benzofuran isophthalate fluorescence. In the in vitro study, primary cortical neurons were prepared from fetuses of ddY mice. Primary cortical neurons were cultured for 5 days before each treatment with reagents, and these survival rates were assessed using biochemical assays. In in vivo study, a mouse model of focal ischaemia was generated using middle cerebral artery occlusion (MCAO). In these experiments, treatment with high concentrations of glucose induced increment in [Na+]i, and this phenomenon was suppressed by the SGLT-specific inhibitor phlorizin. SGLT-specific sodium ion influx was induced using a-methyl-D-glucopyranoside (a-MG) treatments, which led to significant concentration-dependent declines in neuronal survival rates and exacerbated hydrogen peroxide-induced neuronal cell death. Moreover, phlorizin ameliorated these effects. Finally, intracerebroventricular administration of a-MG exacerbated the development of neuronal damage induced by MCAO, and these effects were ameliorated by the administration of phlorizin. Hence, excessive influx of sodium ions into neuronal cells through cerebral SGLT may exacerbate the development of cerebral ischaemic neuronal damage. © 2016 Royal Pharmaceutical Society.

Children’s Depressive Symptoms in Relation to EEG Frontal Asymmetry and Maternal Depression

PubMed Central

Feng, Xin; Forbes, Erika E.; Kovacs, Maria; George, Charles J.; Lopez-Duran, Nestor L.; Fox, Nathan A.; Cohn, Jeffrey F.

2011-01-01

This study examined the relations of school-age children’s depressive symptoms, frontal EEG asymmetry, and maternal history of childhood-onset depression (COD). Participants were 73 children, 43 of whom had mothers with COD. Children’s EEG was recorded at baseline and while watching happy and sad film clips. Depressive symptoms were measured using parent-report of Children’s Depression Inventory. The key findings are the interaction effects between baseline and film frontal EEG asymmetry on child depressive symptoms. Specifically, relative right frontal EEG asymmetry while watching happy or sad film clip was associated with elevated depressive symptoms for children who also exhibited right frontal EEG asymmetry at baseline. Results suggest that right frontal EEG asymmetry that is consistent across situations may be an marker of depression-prone children. PMID:21894523

Brain structural and functional asymmetry in human situs inversus totalis.

PubMed

Vingerhoets, Guy; Li, Xiang; Hou, Lewis; Bogaert, Stephanie; Verhelst, Helena; Gerrits, Robin; Siugzdaite, Roma; Roberts, Neil

2018-05-01

Magnetic resonance imaging was used to investigate brain structural and functional asymmetries in 15 participants with complete visceral reversal (situs inversus totalis, SIT). Language-related brain structural and functional lateralization of SIT participants, including peri-Sylvian gray and white matter asymmetries and hemispheric language dominance, was similar to those of 15 control participants individually matched for sex, age, education, and handedness. In contrast, the SIT cohort showed reversal of the brain (Yakovlevian) torque (occipital petalia and occipital bending) compared to the control group. Secondary findings suggested different asymmetry patterns between SIT participants with (n = 6) or without (n = 9) primary ciliary dyskinesia (PCD, also known as Kartagener syndrome) although the small sample sizes warrant cautious interpretation. In particular, reversed brain torque was mainly due to the subgroup with PCD-unrelated SIT and this group also included 55% left handers, a ratio close to a random allocation of handedness. We conclude that complete visceral reversal has no effect on the lateralization of brain structural and functional asymmetries associated with language, but seems to reverse the typical direction of the brain torque in particular in participants that have SIT unrelated to PCD. The observed differences in asymmetry patterns of SIT groups with and without PCD seem to suggest that symmetry breaking of visceral laterality, brain torque, and language dominance rely on different mechanisms.

Right-frontal cortical asymmetry predicts increased proneness to nostalgia.

PubMed

Tullett, Alexa M; Wildschut, Tim; Sedikides, Constantine; Inzlicht, Michael

2015-08-01

Nostalgia is often triggered by feelings-such as sadness, loneliness, or meaninglessness-that are typically associated with withdrawal motivation. Here, we examined whether a trait tendency to experience withdrawal motivation is associated with nostalgia proneness. Past work indicates that baseline right-frontal cortical asymmetry is a neural correlate of withdrawal-related motivation. We therefore hypothesized that higher baseline levels of right-frontal asymmetry would predict increased proneness to nostalgia. We assessed participants' baseline levels of frontal cortical activity using EEG. Results supported the hypothesis and demonstrated that the association between relative right-frontal asymmetry and increased nostalgia remained significant when controlling for the Big Five personality traits. Overall, these findings indicate that individuals with a stronger dispositional tendency to experience withdrawal-related motivation are more prone to nostalgia. © 2015 Society for Psychophysiological Research.

A full picture of large lepton number asymmetries of the Universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barenboim, Gabriela; Park, Wan-Il, E-mail: Gabriela.Barenboim@uv.es, E-mail: wipark@jbnu.ac.kr

A large lepton number asymmetry of O(0.1−1) at present Universe might not only be allowed but also necessary for consistency among cosmological data. We show that, if a sizeable lepton number asymmetry were produced before the electroweak phase transition, the requirement for not producing too much baryon number asymmetry through sphalerons processes, forces the high scale lepton number asymmetry to be larger than about 03. Therefore a mild entropy release causing O(10-100) suppression of pre-existing particle density should take place, when the background temperature of the Universe is around T = O(10{sup −2}-10{sup 2}) GeV for a large but experimentallymore » consistent asymmetry to be present today. We also show that such a mild entropy production can be obtained by the late-time decays of the saxion, constraining the parameters of the Peccei-Quinn sector such as the mass and the vacuum expectation value of the saxion field to be m {sub φ} ∼> O(10) TeV and φ{sub 0} ∼> O(10{sup 14}) GeV, respectively.« less

Static innominate asymmetry and leg length discrepancy in asymptomatic collegiate athletes.

PubMed

Krawiec, C J; Denegar, C R; Hertel, J; Salvaterra, G F; Buckley, W E

2003-11-01

The objectives of the study were to assess: (1) static innominate asymmetry in the sagittal plane, (2) leg length discrepancy (LLD), and (3) the relationship between static innominate rotation and LLD in asymptomatic collegiate athletes. The study was an observational study by design which took place in a University athletic training research laboratory. The participants were twenty-four male and 20 female asymptomatic intercollegiate athletes who volunteered to take part in the study. Static innominate asymmetry was assessed with a caliper/inclinometer tool and LLD was measured with a tape measure using standard clinical methods. Results showed that forty-two subjects (95%) demonstrated some degree of static innominate asymmetry. In 32 subjects (73%), the right innominate was more anteriorly rotated than the left. Nearly all subjects were determined to have unequal leg lengths with a majority, 30 subjects (68%), showing a slightly longer left leg. Weak correlations (r=0.33 - 0.44) were identified between static innominate asymmetry and LLD. In Conclusion static innominate asymmetry and LLD are common among asymptomatic collegiate athletes. This information provides clinicians with normative data of common clinical measures in a physically active population.

Initial experience of a novel sheath guide for transbrachial coil embolization of cerebral aneurysms in the anterior cerebral circulation.

PubMed

Iwata, Tomonori; Mori, Takahisa; Tajiri, Hiroyuki; Miyazaki, Yuichi; Nakazaki, Masahito; Mizokami, Koji

2013-03-01

The transfemoral approach is a common technique for coil embolization of cerebral aneurysms in the anterior cerebral circulation. However, it is difficult to advance a guiding catheter into the carotid artery via the femoral route in patients with a tortuous aortic arch, an unfavorable supra-aortic takeoff, aortic diseases, or occlusion of the femoral artery. To report our initial experiences of coil embolization of cerebral aneurysms in the anterior cerebral circulation with a novel sheath guide for transbrachial carotid cannulation. A sheath guide designed specifically for transbrachial carotid cannulation was developed; transbrachial coil embolization for cerebral aneurysms began in May 2011. Included for analysis were patients who underwent transbrachial coil embolization for cerebral aneurysms in the anterior cerebral circulation from May 2011 to January 2012. Adjuvant techniques, angiographic results, procedural success, and periprocedural complications were investigated. Ten patients underwent transbrachial coil embolization of cerebral aneurysms in the anterior cerebral circulation. All procedures were successful using the brachial route. No periprocedural complications occurred. Patients were permitted to get seated immediately after coil embolization even during hemostasis. The sheath guide specifically designed for transbrachial carotid cannulation was useful for coil embolization of cerebral aneurysms in the anterior cerebral circulation.

In-flight observations of low-mode ρR asymmetries in NIF implosionsa)

NASA Astrophysics Data System (ADS)

Zylstra, A. B.; Frenje, J. A.; Séguin, F. H.; Rygg, J. R.; Kritcher, A.; Rosenberg, M. J.; Rinderknecht, H. G.; Hicks, D. G.; Friedrich, S.; Bionta, R.; Meezan, N. B.; Olson, R.; Atherton, J.; Barrios, M.; Bell, P.; Benedetti, R.; Berzak Hopkins, L.; Betti, R.; Bradley, D.; Callahan, D.; Casey, D.; Collins, G.; Dewald, E. L.; Dixit, S.; Döppner, T.; Edwards, M. J.; Gatu Johnson, M.; Glenn, S.; Grim, G.; Hatchett, S.; Jones, O.; Khan, S.; Kilkenny, J.; Kline, J.; Knauer, J.; Kyrala, G.; Landen, O.; LePape, S.; Li, C. K.; Lindl, J.; Ma, T.; Mackinnon, A.; Manuel, M. J.-E.; Meyerhofer, D.; Moses, E.; Nagel, S. R.; Nikroo, A.; Parham, T.; Pak, A.; Petrasso, R. D.; Prasad, R.; Ralph, J.; Robey, H. F.; Ross, J. S.; Sangster, T. C.; Sepke, S.; Sinenian, N.; Sio, H. W.; Spears, B.; Tommasini, R.; Town, R.; Weber, S.; Wilson, D.; Yeamans, C.; Zacharias, R.

2015-05-01

Charged-particle spectroscopy is used to assess implosion symmetry in ignition-scale indirect-drive implosions for the first time. Surrogate D3He gas-filled implosions at the National Ignition Facility produce energetic protons via D+3He fusion that are used to measure the implosion areal density (ρR) at the shock-bang time. By using protons produced several hundred ps before the main compression bang, the implosion is diagnosed in-flight at a convergence ratio of 3-5 just prior to peak velocity. This isolates acceleration-phase asymmetry growth. For many surrogate implosions, proton spectrometers placed at the north pole and equator reveal significant asymmetries with amplitudes routinely ≳ 10 % , which are interpreted as ℓ = 2 Legendre modes. With significant expected growth by stagnation, it is likely that these asymmetries would degrade the final implosion performance. X-ray self-emission images at stagnation show asymmetries that are positively correlated with the observed in-flight asymmetries and comparable in magnitude, contradicting growth models; this suggests that the hot-spot shape does not reflect the stagnated shell shape or that significant residual kinetic energy exists at stagnation. More prolate implosions are observed when the laser drive is sustained ("no-coast"), implying a significant time-dependent asymmetry in peak drive.

Fluctuating Dermatoglyphic Asymmetries in Youth at Ultrahigh-risk for Psychotic Disorders

PubMed Central

Russak, Olivia Diane Fern; Ives, Lindsay; Mittal, Vijay A.; Dean, Derek J.

2015-01-01

Fluctuating dermatoglyphic asymmetry represents one specific class of minor physical anomaly that has been proposed to reflect prenatal insult and vulnerability to psychosis. However, very little is known about fluctuating dermatoglyphic asymmetry in youth showing symptoms of ultrahigh risk (UHR) for psychosis. Using high-resolution photographs of fingerprints and clinical interviews, the UHR group in this study showed greater fluctuating dermatoglyphic asymmetry compared to controls; however, this was not further linked to symptomatology. The results of this study provide an important perspective on potential biomarkers and support neurodevelopmental conceptions of psychosis. PMID:26723845

Therapeutic interventions in cerebral palsy.

PubMed

Patel, Dilip R

2005-11-01

Various therapeutic interventions have been used in the management of children with cerebral palsy. Traditional physiotherapy and occupational therapy are widely used interventions and have been shown to be of benefit in the treatment of cerebral palsy. Evidence in support of the effectiveness of the neurodevelopmental treatment is equivocal at best. There is evidence to support the use and effectiveness of neuromuscular electrical stimulation in children with cerebral palsy. The effectiveness of many other interventions used in the treatment of cerebral palsy has not been clearly established based on well-controlled trials. These include: sensory integration, body-weight support treadmill training, conductive education, constraint-induced therapy, hyperbaric oxygen therapy, and the Vojta method. This article provides an overview of salient aspects of popular interventions used in the management of children with cerebral palsy.

Quantifying Normal Craniofacial Form and Baseline Craniofacial Asymmetry in the Pediatric Population.

PubMed

Cho, Min-Jeong; Hallac, Rami R; Ramesh, Jananie; Seaward, James R; Hermann, Nuno V; Darvann, Tron A; Lipira, Angelo; Kane, Alex A

2018-03-01

Restoring craniofacial symmetry is an important objective in the treatment of many craniofacial conditions. Normal form has been measured using anthropometry, cephalometry, and photography, yet all of these modalities have drawbacks. In this study, the authors define normal pediatric craniofacial form and craniofacial asymmetry using stereophotogrammetric images, which capture a densely sampled set of points on the form. After institutional review board approval, normal, healthy children (n = 533) with no known craniofacial abnormalities were recruited at well-child visits to undergo full head stereophotogrammetric imaging. The children's ages ranged from 0 to 18 years. A symmetric three-dimensional template was registered and scaled to each individual scan using 25 manually placed landmarks. The template was deformed to each subject's three-dimensional scan using a thin-plate spline algorithm and closest point matching. Age-based normal facial models were derived. Mean facial asymmetry and statistical characteristics of the population were calculated. The mean head asymmetry across all pediatric subjects was 1.5 ± 0.5 mm (range, 0.46 to 4.78 mm), and the mean facial asymmetry was 1.2 ± 0.6 mm (range, 0.4 to 5.4 mm). There were no significant differences in the mean head or facial asymmetry with age, sex, or race. Understanding the "normal" form and baseline distribution of asymmetry is an important anthropomorphic foundation. The authors present a method to quantify normal craniofacial form and baseline asymmetry in a large pediatric sample. The authors found that the normal pediatric craniofacial form is asymmetric, and does not change in magnitude with age, sex, or race.

Integrative Medicine and Complementary and Alternative Therapies

MedlinePlus

... and tai chi. Questions to Ask Your Healthcare Team Use the following questions as a guide to discuss complementary therapies with your healthcare team: Are there complementary therapies that you would recommend? ...

Cerebral Palsy Litigation

PubMed Central

Sartwelle, Thomas P.

2015-01-01

The cardinal driver of cerebral palsy litigation is electronic fetal monitoring, which has continued unabated for 40 years. Electronic fetal monitoring, however, is based on 19th-century childbirth myths, a virtually nonexistent scientific foundation, and has a false positive rate exceeding 99%. It has not affected the incidence of cerebral palsy. Electronic fetal monitoring has, however, increased the cesarian section rate, with the expected increase in mortality and morbidity risks to mothers and babies alike. This article explains why electronic fetal monitoring remains endorsed as efficacious in the worlds’ labor rooms and courtrooms despite being such a feeble medical modality. It also reviews the reasons professional organizations have failed to condemn the use of electronic fetal monitoring in courtrooms. The failures of tort reform, special cerebral palsy courts, and damage limits to stem the escalating litigation are discussed. Finally, the authors propose using a currently available evidence rule—the Daubert doctrine that excludes “junk science” from the courtroom—as the beginning of the end to cerebral palsy litigation and electronic fetal monitoring’s 40-year masquerade as science. PMID:25183322

Fluctuating Asymmetry and General Intelligence: No Genetic or Phenotypic Association

ERIC Educational Resources Information Center

Johnson, Wendy; Segal, Nancy L.; Bouchard, Thomas J., Jr.

2008-01-01

Fluctuating asymmetry (FA) is the non-pathological left-right asymmetry of body traits that are usually left-right symmetrical, such as eye breadths and elbow to wrist lengths in humans, but which can be affected by developmental stressors. It is generally considered throughout biology to be an indicator of developmental instability and thus of…

Detraditionalisation, gender and alternative and complementary medicines.

PubMed

Sointu, Eeva

2011-03-01

This article is premised on the importance of locating the appeal and meaning of alternative and complementary medicines in the context of gendered identities. I argue that the discourse of wellbeing--captured in many alternative and complementary health practices--is congruent with culturally prevalent ideals of self-fulfilling, authentic, unique and self-responsible subjectivity. The discourse of wellbeing places the self at the centre, thus providing a contrast with traditional ideas of other-directed and caring femininity. As such, involvement in alternative and complementary medicines is entwined with a negotiation of shifting femininities in detraditionalising societies. Simultaneously, many alternative and complementary health practices readily tap into and reproduce traditional representations of caring femininity. It is through an emphasis on emotional honesty and intimacy that the discourse of wellbeing also captures a challenge to traditional ideas of masculinity. Expectations and experiences relating to gender add a further level of complexity to the meaningfulness and therapeutic value of alternative and complementary medicines and underlie the gender difference in the utilisation of holistic health practices. I draw on data from a qualitative study with 44, primarily white, middle-class users and practitioners of varied alternative and complementary medicines in the UK. © 2010 The Author. Sociology of Health & Illness © 2010 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

Theoretical morphology and development of flight feather vane asymmetry with experimental tests in parrots.

PubMed

Feo, Teresa J; Prum, Richard O

2014-06-01

Asymmetry in flight feather vane width is a major functional innovation associated with the evolution of flight in the ancestors of birds. However, the developmental and morphological basis of feather shape is not simple, and the developmental processes involved in vane width asymmetry are poorly understood. We present a theoretical model of feather morphology and development that describes the possible ways to modify feather development and produce vane asymmetry. Our model finds that the theoretical morphospace of feather shape is redundant, and that many different combinations of parameters could be responsible for vane asymmetry in a given feather. Next, we empirically measured morphological and developmental model parameters in asymmetric and symmetric feathers from two species of parrots to identify which combinations of parameters create vane asymmetry in real feathers. We found that both longer barbs, and larger barb angles in the relatively wider trailing vane drove asymmetry in tail feathers. Developmentally, longer barbs were the result of an offset of the radial position of the new barb locus, whereas larger barb angles were produced by differential expansion of barbs as the feather unfurls from the tubular feather germ. In contrast, the helical angle of barb ridge development did not contribute to vane asymmetry and could be indicative of a constraint. This research provides the first comprehensive description of both the morphological and developmental modifications responsible for vane asymmetry within real feathers, and identifies key steps that must have occurred during the evolution of vane asymmetry. © 2014 Wiley Periodicals, Inc.

Cerebral amyloid angiopathy increases susceptibility to infarction after focal cerebral ischemia in Tg2576 mice.

PubMed

Milner, Eric; Zhou, Meng-Liang; Johnson, Andrew W; Vellimana, Ananth K; Greenberg, Jacob K; Holtzman, David M; Han, Byung Hee; Zipfel, Gregory J

2014-10-01

We and others have shown that soluble amyloid β-peptide (Aβ) and cerebral amyloid angiopathy (CAA) cause significant cerebrovascular dysfunction in mutant amyloid precursor protein (APP) mice, and that these deficits are greater in aged APP mice having CAA compared with young APP mice lacking CAA. Amyloid β-peptide in young APP mice also increases infarction after focal cerebral ischemia, but the impact of CAA on ischemic brain injury is unknown. To determine this, we assessed cerebrovascular reactivity, cerebral blood flow (CBF), and extent of infarction and neurological deficits after transient middle cerebral artery occlusion in aged APP mice having extensive CAA versus young APP mice lacking CAA (and aged-matched littermate controls). We found that aged APP mice have more severe cerebrovascular dysfunction that is CAA dependent, have greater CBF compromise during and immediately after middle cerebral artery occlusion, and develop larger infarctions after middle cerebral artery occlusion. These data indicate CAA induces a more severe form of cerebrovascular dysfunction than amyloid β-peptide alone, leading to intra- and postischemic CBF deficits that ultimately exacerbate cerebral infarction. Our results shed mechanistic light on human studies identifying CAA as an independent risk factor for ischemic brain injury. © 2014 American Heart Association, Inc.

Impact of Stratospheric Ozone Zonal Asymmetries on the Tropospheric Circulation

NASA Technical Reports Server (NTRS)

Tweedy, Olga; Waugh, Darryn; Li, Feng; Oman, Luke

2015-01-01

The depletion and recovery of Antarctic ozone plays a major role in changes of Southern Hemisphere (SH) tropospheric climate. Recent studies indicate that the lack of polar ozone asymmetries in chemistry climate models (CCM) leads to a weaker and warmer Antarctic vortex, and smaller trends in the tropospheric mid-latitude jet and the surface pressure. However, the tropospheric response to ozone asymmetries is not well understood. In this study we report on a series of integrations of the Goddard Earth Observing System Chemistry Climate Model (GEOS CCM) to further examine the effect of zonal asymmetries on the state of the stratosphere and troposphere. Integrations with the full, interactive stratospheric chemistry are compared against identical simulations using the same CCM except that (1) the monthly mean zonal mean stratospheric ozone from first simulation is prescribed and (2) ozone is relaxed to the monthly mean zonal mean ozone on a three day time scale. To analyze the tropospheric response to ozone asymmetries, we examine trends and quantify the differences in temperatures, zonal wind and surface pressure among the integrations.

North-south asymmetries in cold ion outflow and lobe density

NASA Astrophysics Data System (ADS)

Haaland, Stein; Laundal, Karl; Maes, Lukas; Baddeley, Lisa; Lybekk, Bjørn

2016-04-01

A significant fraction of the plasma in the terrestrial magnetosphere is supplied by the high-latitude ionosphere. The filling process starts with ionization of atoms and gas molecules in the thermosphere, and is often accompanied by upflow due to thermal and electromagnetic forces. Some of this material can reach escape velocities and be further accelerated and eventually evacuated into space. Ions are governed by electromagnetic forces and their transport path from the ionosphere to the magnetosphere go through the magnetotail lobes. The transport is largely dictated by magnetospheric convection. External influences, such as daily and seasonal variations in the Earth's tilt angle, but also non-dipolar terms in the Earth's internal magnetic field introduce north-south asymmetries in the magnetic field and thus north-south asymmetries in the ion outflow and lobe filling. In this presentation, we show observational results of this asymmetry. The results are based on more than a full solar cycle of cold ion measurements from the Cluster constellation of spacecraft, and allows us to quantify the outflow, identify sources of asymmetry and estimate transport paths.

Study of the s - s bar asymmetry in the proton

NASA Astrophysics Data System (ADS)

Goharipour, Muhammad

2018-05-01

The study of s - s bar asymmetry is essential to better understand of the structure of nucleon and also the perturbative and nonperturbative mechanisms for sea quark generation. Actually, the nature and dynamical origins of this asymmetry have always been an interesting subject to research both experimentally and theoretically. One of the most powerful models can lead to s - s bar asymmetry is the meson-baryon model (MBM). In this work, using a simplified configuration of this model suggested by Pumplin, we calculate the s - s bar asymmetry for different values of cutoff parameter Λ, to study the dependence of model to this parameter and also to estimate the theoretical uncertainty imposed on the results due to its uncertainty. Then, we study the evolution of distributions obtained both at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) using different evolution schemes. It is shown that the evolution of the intrinsic quark distributions from a low initial scale, as suggested by Chang and Pang, is not a good choice at NNLO using variable flavor number scheme (VFNS).

ENSO Transition Asymmetry: Internal and External Causes and Intermodel Diversity

NASA Astrophysics Data System (ADS)

An, Soon-Il; Kim, Ji-Won

2018-05-01

El Niño is frequently followed by La Niña, but the opposite case rarely happens. Here we explore a mechanism for such an asymmetrical transition and its future changes. Internally, the asymmetrical response of upper ocean waves against surface wind stress anomaly exerts a primary cause of El Niño-Southern Oscillation (ENSO) transition asymmetry. Externally, the asymmetrical capacitor effects of both Indian and Atlantic Oceans play some roles in driving the ENSO transition asymmetry via the interbasin interactions. The historical runs of Coupled Model Intercomparison Project Phase 5 show that the intermodel transition asymmetry is significantly correlated with the intermodel asymmetry in ocean wave response to surface wind forcing but not with that in the interbasin interactions. In addition, the El Niño-to-La Niña transition tendency was weaker in moderate global warming scenario runs (Representative Concentration Pathway 4.5) while slightly enhanced in strong warming scenario runs (Representative Concentration Pathway 8.5). Similar changes also appeared in the asymmetrical response of ocean waves against the surface wind forcing.

Gender asymmetry in concurrent partnerships and HIV prevalence.

PubMed

Leung, Ka Yin; Powers, Kimberly A; Kretzschmar, Mirjam

2017-06-01

The structure of the sexual network of a population plays an essential role in the transmission of HIV. Concurrent partnerships, i.e. partnerships that overlap in time, are important in determining this network structure. Men and women may differ in their concurrent behavior, e.g. in the case of polygyny where women are monogamous while men may have concurrent partnerships. Polygyny has been shown empirically to be negatively associated with HIV prevalence, but the epidemiological impacts of other forms of gender-asymmetric concurrency have not been formally explored. Here we investigate how gender asymmetry in concurrency, including polygyny, can affect the disease dynamics. We use a model for a dynamic network where individuals may have concurrent partners. The maximum possible number of simultaneous partnerships can differ for men and women, e.g. in the case of polygyny. We control for mean partnership duration, mean lifetime number of partners, mean degree, and sexually active lifespan. We assess the effects of gender asymmetry in concurrency on two epidemic phase quantities (R 0 and the contribution of the acute HIV stage to R 0 ) and on the endemic HIV prevalence. We find that gender asymmetry in concurrent partnerships is associated with lower levels of all three epidemiological quantities, especially in the polygynous case. This effect on disease transmission can be attributed to changes in network structure, where increasing asymmetry leads to decreasing network connectivity. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Signs of Asymmetry in Exploding Stars

NASA Astrophysics Data System (ADS)

Hensley, Kerry

2018-03-01

Supernova explosions enrich the interstellar medium and can even briefly outshine their host galaxies. However, the mechanism behind these massive explosions still isnt fully understood. Could probing the asymmetry of supernova remnants help us better understand what drives these explosions?Hubble image of the remnant of supernova 1987A, one of the first remnants discovered to be asymmetrical. [ESA/Hubble, NASA]Stellar Send-OffsHigh-mass stars end their lives spectacularly. Each supernova explosion churns the interstellar medium and unleashes high-energy radiation and swarms of neutrinos. Supernovae also suffuse the surrounding interstellar medium with heavy elements that are incorporated into later generations of stars and the planets that form around them.The bubbles of expanding gas these explosions leave behind often appear roughly spherical, but mounting evidence suggests that many supernova remnants are asymmetrical. While asymmetry in supernova remnants can arise when the expanding material plows into the non-uniform interstellar medium, it can also be an intrinsic feature of the explosion itself.Simulation results clockwise from top left: Mass density, calcium mass fraction, oxygen mass fraction, nickel-56 mass fraction. Click to enlarge. [Adapted from Wollaeger et al. 2017]Coding ExplosionsThe presence or absence of asymmetry in a supernova remnant can hold clues as to what drove the explosion. But how can we best observe asymmetry in a supernova remnant? Modeling lets us explore different observational approaches.A team of scientists led by Ryan T. Wollaeger (Los Alamos National Laboratory) used radiative transfer and radiative hydrodynamics simulations to model the explosion of a core-collapse supernova. Wollaeger and collaborators introduced asymmetry into the explosion by creating a single-lobed, fast-moving outflow along one axis.Their simulations showed that while some chemical elements lingered near the origin of the explosion or were distributed

Morphologic evaluation and classification of facial asymmetry using 3-dimensional computed tomography.

PubMed

Baek, Chaehwan; Paeng, Jun-Young; Lee, Janice S; Hong, Jongrak

2012-05-01

A systematic classification is needed for the diagnosis and surgical treatment of facial asymmetry. The purposes of this study were to analyze the skeletal structures of patients with facial asymmetry and to objectively classify these patients into groups according to these structural characteristics. Patients with facial asymmetry and recent computed tomographic images from 2005 through 2009 were included in this study, which was approved by the institutional review board. Linear measurements, angles, and reference planes on 3-dimensional computed tomograms were obtained, including maxillary (upper midline deviation, maxilla canting, and arch form discrepancy) and mandibular (menton deviation, gonion to midsagittal plane, ramus height, and frontal ramus inclination) measurements. All measurements were analyzed using paired t tests with Bonferroni correction followed by K-means cluster analysis using SPSS 13.0 to determine an objective classification of facial asymmetry in the enrolled patients. Kruskal-Wallis test was performed to verify differences among clustered groups. P < .05 was considered statistically significant. Forty-three patients (18 male, 25 female) were included in the study. They were classified into 4 groups based on cluster analysis. Their mean age was 24.3 ± 4.4 years. Group 1 included subjects (44% of patients) with asymmetry caused by a shift or lateralization of the mandibular body. Group 2 included subjects (39%) with a significant difference between the left and right ramus height with menton deviation to the short side. Group 3 included subjects (12%) with atypical asymmetry, including deviation of the menton to the short side, prominence of the angle/gonion on the larger side, and reverse maxillary canting. Group 4 included subjects (5%) with severe maxillary canting, ramus height differences, and menton deviation to the short side. In this study, patients with asymmetry were classified into 4 statistically distinct groups according to

Mitigating the impact of hohlraum asymmetries in National Ignition Facility implosions using capsule shims

NASA Astrophysics Data System (ADS)

Clark, Daniel; Weber, Christopher; Smalyuk, Vladimir; Robey, Harry; Kritcher, Andrea; Milovich, Jose; Salmonson, Jay

2016-10-01

Current indirect drive implosion experiments on the National Ignition Facility (NIF) are believed to be strongly impacted by long wavelength perturbations driven by asymmetries in the hohlraum x-ray flux. To address this perturbation source, active efforts are underway to develop modified hohlraum designs with reduced asymmetry imprint. An alternative strategy, however, is to modify the capsule design to be more resilient to a given amount of hohlraum asymmetry. In particular, the capsule may be deliberately misshaped, or ``shimmed,'' so as to counteract the expected asymmetries from the hohlraum. Here, the efficacy of capsule shimming to correct the asymmetries in two recent NIF implosion experiments is assessed using two-dimensional radiation hydrodynamics simulations. Despite the highly time-dependent character of the asymmetries and the high convergence ratios of these implosions, simulations suggest that shims could be highly effective at counteracting current asymmetries and result in factors of a few enhancements in neutron yields. For higher compression designs, the yield improvement could be even greater. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Effects of hyperbaric oxygen on intracranial pressure and cerebral blood flow in experimental cerebral oedema1

PubMed Central

Miller, J. D.; Ledingham, I. McA.; Jennett, W. B.

1970-01-01

Increased intracranial pressure was induced in anaesthetized dogs by application of liquid nitrogen to the dura mater. Intracranial pressure and cerebral blood flow were measured, together with arterial blood pressure and arterial and cerebral venous blood gases. Carbon dioxide was administered intermittently to test the responsiveness of the cerebral circulation, and hyperbaric oxygen was delivered at intervals in a walk-in hyperbaric chamber, pressurized to two atmospheres absolute. Hyperbaric oxygen caused a 30% reduction of intracranial pressure and a 19% reduction of cerebral blood flow in the absence of changes in arterial PCO2 or blood pressure, but only as long as administration of carbon dioxide caused an increase in both intracranial pressure and cerebral blood flow. When carbon dioxide failed to influence intracranial pressure or cerebral blood flow then hyperbaric oxygen had no effect. This unresponsive state was reached at high levels of intracranial pressure. Images PMID:5497875

[A case of severe asthma exacerbation complicated with cerebral edema and diffuse multiple cerebral micro-bleeds].

PubMed

Ohkura, Noriyuki; Fujimura, Masaki; Sakai, Asao; Fujita, Kentaro; Katayama, Nobuyuki

2009-08-01

A 36-year-old woman was admitted to the Intensive Care Unit for the treatment of severe asthma exacerbation. Her condition of asthma improved with systemic glucocorticosteroids, inhaled beta2-agonist, intravenous theophylline and inhaled anesthesia (isoflurane) under mechanical ventilation. Her consciousness was disturbed even after terminating isoflurane. Brain CT and MRI scan showed cerebral edema and diffuse multiple cerebral micro-bleeds. Glyceol, a hyperosmotic diuretic solution consisting of 10% glycerol and 5% fructose in saline, was administered to decrease cerebral edema. Her consciousness disturbance gradually recovered. Cerebral edema and hemorrhage improved. On the 69th hospital day, she was discharged from hospital without sequelae. This case is a rare one in which severe asthma exacerbation was complicated with cerebral edema and diffuse multiple cerebral hemorrhage. Inhaled anesthesia for asthma exacerbation should be used carefully to avoid delay of diagnosis of central nervous system complications.

Perception of risk and communication among conventional and complementary health care providers involving cancer patients' use of complementary therapies: a literature review.

PubMed

Stub, Trine; Quandt, Sara A; Arcury, Thomas A; Sandberg, Joanne C; Kristoffersen, Agnete E; Musial, Frauke; Salamonsen, Anita

2016-09-08

Communication between different health care providers (conventional and complementary) and cancer patients about their use of complementary therapies affects the health and safety of the patients. The aim of this study was to examine the qualitative research literature on the perception of and communication about the risk of complementary therapies between different health care providers and cancer patients. Systematic searches in six medical databases covering literature from 2000 to 2015 were performed. The studies were accessed according to the level of evidence and summarized into different risk situations. Qualitative content analysis was used to analyze the text data, and the codes were defined before and during the data analysis. Twenty-nine papers were included in the primary analysis and five main themes were identified and discussed. The main risk situations identified were 1. Differences in treatment concepts and philosophical values among complementary and conventional health care providers. 2. Adverse effects from complementary products and herbs due to their contamination/toxicity and interactions with conventional cancer treatment. 3. Health care physicians and oncologists find it difficult to recommend many complementary modalities due to the lack of scientific evidence for their effect. 4. Lack of knowledge and information about complementary and conventional cancer treatments among different health care providers. The risk of consuming herbs and products containing high level of toxins is a considerable threat to patient safety (direct risk). At the same time, the lack of scientific evidence of effect for many complementary therapies and differences in treatment philosophy among complementary and conventional health care providers potentially hinder effective communication about these threats with mutual patients (indirect risk). As such, indirect risk may pose an additional risk to patients who want to combine complementary therapies with

Genetic specification of left-right asymmetry in the diaphragm muscles and their motor innervation.

PubMed

Charoy, Camille; Dinvaut, Sarah; Chaix, Yohan; Morlé, Laurette; Sanyas, Isabelle; Bozon, Muriel; Kindbeiter, Karine; Durand, Bénédicte; Skidmore, Jennifer M; De Groef, Lies; Seki, Motoaki; Moons, Lieve; Ruhrberg, Christiana; Martin, James F; Martin, Donna M; Falk, Julien; Castellani, Valerie

2017-06-22

The diaphragm muscle is essential for breathing in mammals. Its asymmetric elevation during contraction correlates with morphological features suggestive of inherent left-right (L/R) asymmetry. Whether this asymmetry is due to L versus R differences in the muscle or in the phrenic nerve activity is unknown. Here, we have combined the analysis of genetically modified mouse models with transcriptomic analysis to show that both the diaphragm muscle and phrenic nerves have asymmetries, which can be established independently of each other during early embryogenesis in pathway instructed by Nodal, a morphogen that also conveys asymmetry in other organs. We further found that phrenic motoneurons receive an early L/R genetic imprint, with L versus R differences both in Slit/Robo signaling and MMP2 activity and in the contribution of both pathways to establish phrenic nerve asymmetry. Our study therefore demonstrates L-R imprinting of spinal motoneurons and describes how L/R modulation of axon guidance signaling helps to match neural circuit formation to organ asymmetry.

Office of Cancer Complementary and Alternative Medicine

MedlinePlus

... Information. Outreach. The Office of Cancer Complementary and Alternative Medicine (OCCAM) was established in October 1998 to coordinate ... Institute (NCI) in the arena of complementary and alternative medicine (CAM). More about us. CAM at the NCI ...

Orthogonal Polynomials Associated with Complementary Chain Sequences

NASA Astrophysics Data System (ADS)

Behera, Kiran Kumar; Sri Ranga, A.; Swaminathan, A.

2016-07-01

Using the minimal parameter sequence of a given chain sequence, we introduce the concept of complementary chain sequences, which we view as perturbations of chain sequences. Using the relation between these complementary chain sequences and the corresponding Verblunsky coefficients, the para-orthogonal polynomials and the associated Szegő polynomials are analyzed. Two illustrations, one involving Gaussian hypergeometric functions and the other involving Carathéodory functions are also provided. A connection between these two illustrations by means of complementary chain sequences is also observed.

Cerebral Palsy (For Kids)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Kids / Cerebral Palsy What's in this ... the things that kids do every day. What's CP? Some kids with CP use wheelchairs and others ...

First measurement of the Sivers asymmetry for gluons using SIDIS data

NASA Astrophysics Data System (ADS)

Adolph, C.; Aghasyan, M.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anfimov, N. V.; Anosov, V.; Antoshkin, A.; Augsten, K.; Augustyniak, W.; Austregesilo, A.; Azevedo, C. D. R.; Badełek, B.; Balestra, F.; Ball, M.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Birsa, R.; Bodlak, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Chang, W.-C.; Chatterjee, C.; Chiosso, M.; Choi, I.; Chung, S.-U.; Cicuttin, A.; Crespo, M. L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Dhara, L.; Donskov, S. V.; Doshita, N.; Dreisbach, Ch.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; Du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Giarra, J.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; Hamar, G.; von Harrach, D.; Heinsius, F. H.; Heitz, R.; Herrmann, F.; Horikawa, N.; D'Hose, N.; Hsieh, C.-Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jary, V.; Joosten, R.; Jörg, P.; Kabuß, E.; Kerbizi, A.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O. M.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lian, Y.-S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G. K.; Marianski, B.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G. V.; Meyer, M.; Meyer, W.; Mikhailov, Yu. V.; Mikhasenko, M.; Mitrofanov, E.; Mitrofanov, N.; Miyachi, Y.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nový, J.; Nowak, W.-D.; Nukazuka, G.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.-C.; Pereira, F.; Pešek, M.; Peshekhonov, D. V.; Pierre, N.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rogacheva, N. S.; Ryabchikov, D. I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schönning, K.; Seder, E.; Selyunin, A.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Srnka, A.; Steffen, D.; Stolarski, M.; Subrt, O.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Thiel, A.; Tosello, F.; Tskhay, V.; Uhl, S.; Vauth, A.; Veloso, J.; Virius, M.; Vondra, J.; Wallner, S.; Weisrock, T.; Wilfert, M.; Ter Wolbeek, J.; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Zhuravlev, N.; Ziembicki, M.; Zink, A.; Compass Collaboration

2017-09-01

The Sivers function describes the correlation between the transverse spin of a nucleon and the transverse motion of its partons. For quarks, it was studied in previous measurements of the azimuthal asymmetry of hadrons produced in semi-inclusive deep inelastic scattering of leptons off transversely polarised nucleon targets, and it was found to be non-zero. In this letter the evaluation of the Sivers asymmetry for gluons is presented. The contribution of the photon-gluon fusion subprocess is enhanced by requiring two high transverse-momentum hadrons. The analysis method is based on a Monte Carlo simulation that includes three hard processes: photon-gluon fusion, QCD Compton scattering and the leading-order virtual-photon absorption process. The Sivers asymmetries of the three processes are simultaneously extracted using the LEPTO event generator and a neural network approach. The method is applied to samples of events containing at least two hadrons with large transverse momentum from the COMPASS data taken with a 160 GeV/c muon beam scattered off transversely polarised deuterons and protons. With a significance of about two standard deviations, a negative value is obtained for the gluon Sivers asymmetry. The result of a similar analysis for a Collins-like asymmetry for gluons is consistent with zero.

Anisotropy and Asymmetry of Yield in Magnesium Alloys at Room Temperature

NASA Astrophysics Data System (ADS)

Robson, Joseph

2014-10-01

Mechanical anisotropy and asymmetry are often pronounced in wrought magnesium alloys and are detrimental to formability and service performance. Single crystals of magnesium are highly anisotropic due to the large difference in critical resolved shear stress between the softest and hardest deformation modes. Polycrystalline magnesium alloys exhibit lower anisotropy, influenced by texture, solute level, and precipitates. In this work, a fundamental study of the effects of alloying, precipitate formation, and texture on the change in anisotropy and asymmetry from the pure magnesium single crystal case to polycrystalline alloys has been performed. It is demonstrated that much of the reduction in anisotropy and asymmetry arises from overall strengthening as solute, precipitates, and grain boundary effects are accounted for. Precipitates are predicted to be more effective than solute in reducing anisotropy and asymmetry, but shape and habit are critical since precipitates produce highly anisotropic strengthening. A small deviation from an ideal basal texture (15 deg spread) has a very strong effect in reducing anisotropy and asymmetry, similar in magnitude to the maximum effect produced by precipitation. Elasto-plastic modeling suggests that this is due to a contribution from basal slip to initial plastic deformation, even when global yield is not controlled by this mode.

In-flight observations of low-mode ρR asymmetries in NIF implosions

DOE PAGES

Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; ...

2015-05-01

Charged-particle spectroscopy is used to assess implosion symmetry in ignition-scale indirect-drive implosions for the first time. Surrogate D 3He gas-filled implosions at the National Ignition Facility produce energetic protons via D+ 3He fusion that are used to measure the implosion areal density (ρR) at the shock-bang time. By using protons produced several hundred ps before the main compression bang, the implosion is diagnosed in-flight at a convergence ratio of 3-5 just prior to peak velocity. This isolates acceleration-phase asymmetry growth. For many surrogate implosions, proton spectrometers placed at the north pole and equator reveal significant asymmetries with amplitudes routinely ≳10%,more » which are interpreted as l=2 Legendre modes. With significant expected growth by stagnation, it is likely that these asymmetries would degrade the final implosion performance. X-ray self-emission images at stagnation show asymmetries that are positively correlated with the observed in-flight asymmetries and comparable in magnitude, contradicting growth models; this suggests that the hot-spot shape does not reflect the stagnated shell shape or that significant residual kinetic energy exists at stagnation. More prolate implosions are observed when the laser drive is sustained (“no-coast”), implying a significant time-dependent asymmetry in peak drive.« less

In-flight observations of low-mode ρR asymmetries in NIF implosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zylstra, A. B., E-mail: zylstra@mit.edu; Frenje, J. A.; Séguin, F. H.

2015-05-15

Charged-particle spectroscopy is used to assess implosion symmetry in ignition-scale indirect-drive implosions for the first time. Surrogate D{sup 3}He gas-filled implosions at the National Ignition Facility produce energetic protons via D+{sup 3}He fusion that are used to measure the implosion areal density (ρR) at the shock-bang time. By using protons produced several hundred ps before the main compression bang, the implosion is diagnosed in-flight at a convergence ratio of 3–5 just prior to peak velocity. This isolates acceleration-phase asymmetry growth. For many surrogate implosions, proton spectrometers placed at the north pole and equator reveal significant asymmetries with amplitudes routinely ≳10%,more » which are interpreted as ℓ=2 Legendre modes. With significant expected growth by stagnation, it is likely that these asymmetries would degrade the final implosion performance. X-ray self-emission images at stagnation show asymmetries that are positively correlated with the observed in-flight asymmetries and comparable in magnitude, contradicting growth models; this suggests that the hot-spot shape does not reflect the stagnated shell shape or that significant residual kinetic energy exists at stagnation. More prolate implosions are observed when the laser drive is sustained (“no-coast”), implying a significant time-dependent asymmetry in peak drive.« less

Measurement and genetics of human subcortical and hippocampal asymmetries in large datasets.

PubMed

Guadalupe, Tulio; Zwiers, Marcel P; Teumer, Alexander; Wittfeld, Katharina; Vasquez, Alejandro Arias; Hoogman, Martine; Hagoort, Peter; Fernandez, Guillen; Buitelaar, Jan; Hegenscheid, Katrin; Völzke, Henry; Franke, Barbara; Fisher, Simon E; Grabe, Hans J; Francks, Clyde

2014-07-01

Functional and anatomical asymmetries are prevalent features of the human brain, linked to gender, handedness, and cognition. However, little is known about the neurodevelopmental processes involved. In zebrafish, asymmetries arise in the diencephalon before extending within the central nervous system. We aimed to identify genes involved in the development of subtle, left-right volumetric asymmetries of human subcortical structures using large datasets. We first tested the feasibility of measuring left-right volume differences in such large-scale samples, as assessed by two automated methods of subcortical segmentation (FSL|FIRST and FreeSurfer), using data from 235 subjects who had undergone MRI twice. We tested the agreement between the first and second scan, and the agreement between the segmentation methods, for measures of bilateral volumes of six subcortical structures and the hippocampus, and their volumetric asymmetries. We also tested whether there were biases introduced by left-right differences in the regional atlases used by the methods, by analyzing left-right flipped images. While many bilateral volumes were measured well (scan-rescan r = 0.6-0.8), most asymmetries, with the exception of the caudate nucleus, showed lower repeatabilites. We meta-analyzed genome-wide association scan results for caudate nucleus asymmetry in a combined sample of 3,028 adult subjects but did not detect associations at genome-wide significance (P < 5 × 10(-8) ). There was no enrichment of genetic association in genes involved in left-right patterning of the viscera. Our results provide important information for researchers who are currently aiming to carry out large-scale genome-wide studies of subcortical and hippocampal volumes, and their asymmetries. Copyright © 2013 Wiley Periodicals, Inc.

Ear Asymmetry for Monaurally Presented Word Lists in Children and Adults.

ERIC Educational Resources Information Center

Burns, Kathy Martindale; Manning, Walter H.

1985-01-01

To study ear asymmetry during monaural stimulation, 80 listeners were asked to recall the word which followed a probe word in 40 10-word lists. Ear asymmetry during monaural stimulation appeared to be related to competition between incoming and rehearsed stimuli during central memory processing. (Author/CL)

Effect of sonic boom asymmetry on subjective loudness

NASA Technical Reports Server (NTRS)

Leatherwood, Jack D.; Sullivan, Brenda M.

1992-01-01

The NASA Langley Research Center's sonic boom apparatus was used in an experimental study to quantify subjective loudness response to a wide range of asymmetrical N-wave sonic boom signatures. Results were used to assess the relative performance of several metrics as loudness estimators for asymmetrical signatures and to quantify in detail the effects on subjective loudness of varying both the degree and direction of signature loudness asymmetry. Findings of the study indicated that Perceived Level (Steven's Mark 7) and A-weighted sound exposure level were the best metrics for quantifying asymmetrical boom loudness. Asymmetrical signatures were generally rated as being less loud than symmetrical signatures of equivalent Perceived Level. The magnitude of the loudness reductions increased as the degree of boom asymmetry increased, and depended upon the direction of asymmetry. These loudness reductions were not accounted for by any of the metrics. Corrections were determined for use in adjusting calculated Perceived Level values to account for these reductions. It was also demonstrated that the subjects generally incorporated the loudness components of the complete signatures when making their subjective judgments.

[The cerebral hemodynamics in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy].

PubMed

Jin, De-xin; Chen, Xiu-yun; Huang, He; Zhang, Xu

2006-12-01

To investigate the cerebral hemodynamics in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The blood flow velocity of cerebral arteries was measured by using transcranial Doppler ultrasound (TCD) in 6 cases with CADASIL and a quite number of age and sex matched control subjects. All patients (4 were symptomatic and 2 asymptomatic), being an established CADASIL family with the diagnosis confirmed by clinical characteristics, neuroimaging, pathology and molecular genetics, had abnormal mark signals on MR imagining and no history of hypertension, diabetes, heart disease and migraine. A routinely TCD detection, including peak-systolic velocity (Vp), end-diastolic velocity (Vd), mean velocity (Vm) and pulsatility index (PI), was carried out on the bilateral middle cerebral arteries (MCA), anterior cerebral arteries (ACA), posterior cerebral arteries (PCA) and vertebral arteries (VA) as well as the basilar artery (BA). A comparison between the cases and controls was made. Then, the changes of flow velocity in middle cerebral arteries (MCA) of the patients with CADASIL were observed before and after breathholding tests. In addition, brain CT perfusion imaging (CTP) was carried out in all the cases by using 16-slice spiral CT. The appearances of frequency spectrum were nearly normal in all the cases and there was no abnormality between the two sides on velocity (P > 0.05). As compared with the controls, the bilateral Vp, Vd and Vm in ACA and PCA were decreased obviously (P < 0.05). The velocity parameters of MCA with the exception of left Vm and right PI showed changes (P < 0.05) and there were no changes of PI in the bilateral ACA, PCA and Left MCA (P > 0.05). Moreover, there were marked changes in MCA (including Vm, Vd and PI) of all the cases as compared with the controls after breathholding (P < 0.01). Brain perfusion imaging showing the regional cerebral blood flow and regional cerebral blood volume in frontal

Molecular pathophysiology of cerebral edema

PubMed Central

Gerzanich, Volodymyr; Simard, J Marc

2015-01-01

Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema. PMID:26661240

A capability model of individual differences in frontal EEG asymmetry.

PubMed

Coan, James A; Allen, John J B; McKnight, Patrick E

2006-05-01

Researchers interested in measuring individual differences in affective style via asymmetries in frontal brain activity have depended almost exclusively upon the resting state for EEG recording. This reflects an implicit conceptualization of affective style as a response predisposition that is manifest in frontal EEG asymmetry, with the goal to describe individuals in terms of their general approach or withdrawal tendencies. Alternatively, the response capability conceptualization seeks to identify individual capabilities for approach versus withdrawal responses during emotionally salient events. The capability approach confers a variety of advantages to the study of affective style and personality, and suggests new possibilities for the approach/withdrawal motivational model of frontal EEG asymmetry and emotion. Logical as well as empirical arguments supportive of this conclusion are presented.

Symptomatic Cerebral Vasospasm and Delayed Cerebral Ischemia Following Transsphenoidal Resection of a Craniopharyngioma.

PubMed

Ricarte, Irapuá Ferreira; Funchal, Bruno F; Miranda Alves, Maramélia A; Gomes, Daniela L; Valiente, Raul A; Carvalho, Flávio A; Silva, Gisele S

2015-09-01

Vasospasm has been rarely described as a complication associated with craniopharyngioma surgery. Herein we describe a patient who developed symptomatic vasospasm and delayed cerebral ischemia after transsphenoidal surgery for a craniopharyngioma. A 67-year-old woman became drowsy 2 weeks after a transsphenoidal resection of a craniopharyngioma. A head computed tomography (CT) was unremarkable except for postoperative findings. Electroencephalogram and laboratory studies were within the normal limits. A repeated CT scan 48 hours after the initial symptoms showed bilateral infarcts in the territory of the anterior cerebral arteries (ACA). Transcranial Doppler (TCD) showed increased blood flow velocities in both anterior cerebral arteries (169 cm/second in the left ACA and 145 cm/second in the right ACA) and right middle cerebral artery (164 cm/second) compatible with vasospasm. A CT angiography confirmed the findings. She was treated with induced hypertension and her level of consciousness improved. TCD velocities normalized after 2 weeks. Cerebral vasospasm should be considered in the differential diagnosis of patients with altered neurologic status in the postoperative period following a craniopharyngioma resection. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors

PubMed Central

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C. P.; Gelinck, Gerwin H.; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-01-01

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics. PMID:27762321

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors.

PubMed

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C P; Gelinck, Gerwin H; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-10-20

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics.

Alpha decay hindrance factors and reflection asymmetry in nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheline, R.K.; Bossinga, B.B.

1991-07-01

All available hindrance factors of alpha transitions to low-lying negative-parity states in doubly even nuclei, to odd-{ital A} parity doublets and to doubly odd parity doublet bands, are used to study the systematics of reflection asymmetry in the {ital A}{similar to}218--230 region. Special attention is given to the polarization effect of the odd particle in increasing reflection asymmetry and therefore decreasing hindrance factors to the opposite parity states of octupole bands.

APOE associated hemispheric asymmetry of entorhinal cortical thickness in aging and Alzheimer’s disease

PubMed Central

Donix, Markus; Burggren, Alison C.; Scharf, Maria; Marschner, Kira; Suthana, Nanthia A.; Siddarth, Prabha; Krupa, Allison K.; Jones, Michael; Martin-Harris, Laurel; Ercoli, Linda M.; Miller, Karen J.; Werner, Annett; von Kummer, Rüdiger; Sauer, Cathrin; Small, Gary W.; Holthoff, Vjera A.; Bookheimer, Susan Y.

2013-01-01

Across species structural and functional hemispheric asymmetry is a fundamental feature of the brain. Environmental and genetic factors determine this asymmetry during brain development and modulate its interaction with brain disorders. The e4 allele of the apolipoprotein E gene (APOE-4) is a risk factor for Alzheimer’s disease, associated with regionally specific effects on brain morphology and function during the life span. Furthermore, entorhinal and hippocampal hemispheric asymmetry could be modified by pathology during Alzheimer’s disease development. Using high-resolution magnetic resonance imaging and a cortical unfolding technique we investigated whether carrying the APOE-4 allele influences hemispheric asymmetry in the entorhinal cortex and the hippocampus among patients with Alzheimer’s disease as well as in middle-aged and older cognitively healthy individuals. APOE-4 carriers showed a thinner entorhinal cortex in the left hemisphere when compared with the right hemisphere across all participants. Non-carriers of the allele showed this asymmetry only in the patient group. Cortical thickness in the hippocampus did not vary between hemispheres among APOE-4 allele carriers and non-carriers. The APOE-4 allele modulates hemispheric asymmetry in entorhinal cortical thickness. Among Alzheimer’s disease patients, this asymmetry might be less dependent on the APOE genotype and a more general marker of incipient disease pathology. PMID:24080518

Enhanced contractility of intraparenchymal arterioles after global cerebral ischaemia in rat - new insights into the development of delayed cerebral hypoperfusion.

PubMed

Spray, S; Johansson, S E; Radziwon-Balicka, A; Haanes, K A; Warfvinge, K; Povlsen, G K; Kelly, P A T; Edvinsson, L

2017-08-01

Delayed cerebral hypoperfusion is a secondary complication found in the days after transient global cerebral ischaemia that worsens the ischaemic damage inflicted by the initial transient episode of global cerebral ischaemia. A recent study demonstrated increased cerebral vasoconstriction in the large arteries on the brain surface (pial arteries) after global cerebral ischaemia. However, smaller arterioles inside the brain (parenchymal arterioles) are equally important in the regulation of cerebral blood flow and yet their pathophysiology after global cerebral ischaemia is largely unknown. Therefore, we investigated whether increased contractility occurs in the intraparenchymal arterioles. Global cerebral ischaemia was induced in male Wistar rats by bilateral common carotid occlusion for 15 min combined with hypovolaemia. Regional cerebral blood flow was determined by quantitative autoradiography. Intraparenchymal arterioles were isolated and pressurized, and concentration-response curves to endothelin-1 with and without the endothelin B receptor-selective antagonist BQ788 was generated. Endothelin B receptor expression was investigated by quantitative flow cytometry and immunohistochemistry. We observed increased endothelin-1-mediated contractility of parenchymal arterioles correlating with reduced cerebral blood flow of the cortex, hippocampus and caudate nucleus 48 h after global cerebral ischaemia. The increased endothelin-1-mediated contractility was abolished by BQ788, and the vascular smooth muscle cell-specific expression of endothelin B receptors was significantly increased after global cerebral ischaemia. Increased endothelin-1-mediated contractility and expression of endothelin B receptors in the intraparenchymal vasculature contributes to the development of delayed cerebral hypoperfusion after global cerebral ischaemia in combination with vascular changes of the pial vasculature. © 2016 Scandinavian Physiological Society. Published by John Wiley

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement.

PubMed

Tanaka, Akiko; Estrera, Anthony L

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field-and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement

PubMed Central

Tanaka, Akiko

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field—and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution. PMID:29682460

Comparing Neutron Star Kicks to Supernova Remnant Asymmetries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland-Ashford, Tyler; Lopez, Laura A.; Auchettl, Katie

2017-07-20

Supernova explosions are inherently asymmetric and can accelerate new-born neutron stars (NSs) to hundreds of km s{sup −1}. Two prevailing theories to explain NS kicks are ejecta asymmetries (e.g., conservation of momentum between NS and ejecta) and anisotropic neutrino emission. Observations of supernova remnants (SNRs) can give us insights into the mechanism that generates these NS kicks. In this paper, we investigate the relationship between NS kick velocities and the X-ray morphologies of 18 SNRs observed with the Chandra X-ray Observatory and the Röntgen Satellite ( ROSAT ). We measure SNR asymmetries using the power-ratio method (a multipole expansion technique),more » focusing on the dipole, quadrupole, and octupole power ratios. Our results show no correlation between the magnitude of the power ratios and NS kick velocities, but we find that for Cas A and G292.0+1.8, whose emission traces the ejecta distribution, their NSs are preferentially moving opposite to the bulk of the X-ray emission. In addition, we find a similar result for PKS 1209–51, CTB 109, and Puppis A; however, their emission is dominated by circumstellar/interstellar material, so their asymmetries may not reflect their ejecta distributions. Our results are consistent with the theory that NS kicks are a consequence of ejecta asymmetries as opposed to anisotropic neutrino emission. In the future, additional observations to measure NS proper motions within ejecta-dominated SNRs are necessary to robustly constrain the NS kick mechanism.« less

Myosin1D is an evolutionarily conserved regulator of animal left-right asymmetry.

PubMed

Juan, Thomas; Géminard, Charles; Coutelis, Jean-Baptiste; Cerezo, Delphine; Polès, Sophie; Noselli, Stéphane; Fürthauer, Maximilian

2018-05-16

The establishment of left-right (LR) asymmetry is fundamental to animal development, but the identification of a unifying mechanism establishing laterality across different phyla has remained elusive. A cilia-driven, directional fluid flow is important for symmetry breaking in numerous vertebrates, including zebrafish. Alternatively, LR asymmetry can be established independently of cilia, notably through the intrinsic chirality of the acto-myosin cytoskeleton. Here, we show that Myosin1D (Myo1D), a previously identified regulator of Drosophila LR asymmetry, is essential for the formation and function of the zebrafish LR organizer (LRO), Kupffer's vesicle (KV). Myo1D controls the orientation of LRO cilia and interacts functionally with the planar cell polarity (PCP) pathway component VanGogh-like2 (Vangl2), to shape a productive LRO flow. Our findings identify Myo1D as an evolutionarily conserved regulator of animal LR asymmetry, and show that functional interactions between Myo1D and PCP are central to the establishment of animal LR asymmetry.

Infant frontal EEG asymmetry in relation with postnatal maternal depression and parenting behavior.

PubMed

Wen, D J; Soe, N N; Sim, L W; Sanmugam, S; Kwek, K; Chong, Y-S; Gluckman, P D; Meaney, M J; Rifkin-Graboi, A; Qiu, A

2017-03-14

Right frontal electroencephalogram (EEG) asymmetry associates with negative affect and depressed mood, which, among children, are predicted by maternal depression and poor parenting. This study examined associations of maternal depression and maternal sensitivity with infant frontal EEG asymmetry based on 111 mother-6-month-infant dyads. There were no significant effects of postnatal maternal depression or maternal sensitivity, or their interaction, on infant EEG frontal asymmetry. However, in a subsample for which the infant spent at least 50% of his/her day time hours with his/her mother, both lower maternal sensitivity and higher maternal depression predicted greater relative right frontal EEG asymmetry. Our study further showed that greater relative right frontal EEG asymmetry of 6-month-old infants predicted their greater negative emotionality at 12 months of age. Our study suggested that among infants with sufficient postnatal maternal exposure, both maternal sensitivity and mental health are important influences on early brain development.

The ontogenesis of the forebrain commissures and the determination of brain asymmetries.

PubMed

Lent, R; Schmidt, S L

1993-02-01

We have reviewed the organization and development of the interhemispheric projections through the forebrain commissures, especially those of the CC, in connection with the development of brain asymmetries. Analyzing the available data, we conclude that the developing CC plays an important role in the ontogenesis of brain asymmetries. We have extended a previous hypothesis that the rodent CC may exert a stabilizing effect over the unstable populational asymmetries of cortical size and shape, and that it participates in the developmental stabilization of lateralized motor behaviors.

Early embryonic programming of neuronal left/right asymmetry in C. elegans.

PubMed

Poole, Richard J; Hobert, Oliver

2006-12-05

Nervous systems are largely bilaterally symmetric on a morphological level but often display striking degrees of functional left/right (L/R) asymmetry. How L/R asymmetric functional features are superimposed onto an essentially bilaterally symmetric structure and how nervous-system laterality relates to the L/R asymmetry of internal organs are poorly understood. We address these questions here by using the establishment of L/R asymmetry in the ASE chemosensory neurons of C. elegans as a paradigm. This bilaterally symmetric neuron pair is functionally lateralized in that it senses a distinct class of chemosensory cues and expresses a putative chemoreceptor family in a L/R asymmetric manner. We show that the directionality of the asymmetry of the two postmitotic ASE neurons ASE left (ASEL) and ASE right (ASER) in adults is dependent on a L-/R-symmetry-breaking event at a very early embryonic stage, the six-cell stage, which also establishes the L/R asymmetric placement of internal organs. However, the L/R asymmetry of the ASE neurons per se is dependent on an even earlier anterior-posterior (A/P) Notch signal that specifies embryonic ABa/ABp blastomere identities at the four-cell stage. This Notch signal, which functions through two T box genes, acts genetically upstream of a miRNA-controlled bistable feedback loop that regulates the L/R asymmetric gene-expression program in the postmitotic ASE cells. Our results link adult neuronal laterality to the generation of the A/P axis at the two-cell stage and raise the possibility that neural asymmetries observed across the animal kingdom are similarly established by very early embryonic interactions.

Dual Logic and Cerebral Coordinates for Reciprocal Interaction in Eye Contact

PubMed Central

Lee, Ray F.

2015-01-01

In order to scientifically study the human brain’s response to face-to-face social interaction, the scientific method itself needs to be reconsidered so that both quantitative observation and symbolic reasoning can be adapted to the situation where the observer is also observed. In light of the recent development of dyadic fMRI which can directly observe dyadic brain interacting in one MRI scanner, this paper aims to establish a new form of logic, dual logic, which provides a theoretical platform for deductive reasoning in a complementary dual system with emergence mechanism. Applying the dual logic in the dfMRI experimental design and data analysis, the exogenous and endogenous dual systems in the BOLD responses can be identified; the non-reciprocal responses in the dual system can be suppressed; a cerebral coordinate for reciprocal interaction can be generated. Elucidated by dual logic deductions, the cerebral coordinate for reciprocal interaction suggests: the exogenous and endogenous systems consist of the empathy network and the mentalization network respectively; the default-mode network emerges from the resting state to activation in the endogenous system during reciprocal interaction; the cingulate plays an essential role in the emergence from the exogenous system to the endogenous system. Overall, the dual logic deductions are supported by the dfMRI experimental results and are consistent with current literature. Both the theoretical framework and experimental method set the stage to formally apply the scientific method in studying complex social interaction. PMID:25885446

Caffeine induced changes in cerebral circulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathew, R.J.; Wilson, W.H.

1985-09-01

While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the TTXenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differencesmore » between the three sets of cerebral blood flow values.« less

Systematic Mapping and Statistical Analyses of Valley Landform and Vegetation Asymmetries Across Hydroclimatic Gradients

NASA Astrophysics Data System (ADS)

Poulos, M. J.; Pierce, J. L.; McNamara, J. P.; Flores, A. N.; Benner, S. G.

2015-12-01

Terrain aspect alters the spatial distribution of insolation across topography, driving eco-pedo-hydro-geomorphic feedbacks that can alter landform evolution and result in valley asymmetries for a suite of land surface characteristics (e.g. slope length and steepness, vegetation, soil properties, and drainage development). Asymmetric valleys serve as natural laboratories for studying how landscapes respond to climate perturbation. In the semi-arid montane granodioritic terrain of the Idaho batholith, Northern Rocky Mountains, USA, prior works indicate that reduced insolation on northern (pole-facing) aspects prolongs snow pack persistence, and is associated with thicker, finer-grained soils, that retain more water, prolong the growing season, support coniferous forest rather than sagebrush steppe ecosystems, stabilize slopes at steeper angles, and produce sparser drainage networks. We hypothesize that the primary drivers of valley asymmetry development are changes in the pedon-scale water-balance that coalesce to alter catchment-scale runoff and drainage development, and ultimately cause the divide between north and south-facing land surfaces to migrate northward. We explore this conceptual framework by coupling land surface analyses with statistical modeling to assess relationships and the relative importance of land surface characteristics. Throughout the Idaho batholith, we systematically mapped and tabulated various statistical measures of landforms, land cover, and hydroclimate within discrete valley segments (n=~10,000). We developed a random forest based statistical model to predict valley slope asymmetry based upon numerous measures (n>300) of landscape asymmetries. Preliminary results suggest that drainages are tightly coupled with hillslopes throughout the region, with drainage-network slope being one of the strongest predictors of land-surface-averaged slope asymmetry. When slope-related statistics are excluded, due to possible autocorrelation, valley

Asymmetry of wind waves studied in a laboratory tank

NASA Astrophysics Data System (ADS)

Ileykin, L. A.; Donelan, M. A.; Mellen, R. H.; McLaughlin, D. J.

1995-03-01

Asymmetry of wind waves was studied in laboratory tank tinder varied wind and fetch conditions using both bispectral analysis of wave records and third-order statistics of the surface elevation. It is found skewness S (the normalized third-order moment of surface elevation describing the horizontal asymmetry waves) varies only slightly with the inverse wave u*/Cm (where u* is the air friction velocity and Cm is phase speed of the dominant waves). At the same time asymmetry A, which is determined from the Hilbert transform of the wave record and characterizes the skewness of the rate of change of surface elevation, increase consistently in magnitude with the ratio u*/Cm. This suggests that nonlinear distortion of the wave profile determined by the degree of wind forcing and is a sensitive indicator of wind-wave interaction processes. It is shown that the asymmetric profile of waves can described within the frameworks of the nonlinear nonspectral concept (Plate, 1972; Lake and Yuen, 197 according to which the wind-wave field can be represented as a coherent bound-wave system consisting mainly of dominant component w. and its harmonics propagating with the same speed C. , as observed by Ramamonjiaris and Coantic (1976). The phase shift between o). harmonics is found and shown to increase with the asymmetry of the waves.

Asymmetry of wind waves studied in a laboratory tank

NASA Astrophysics Data System (ADS)

Leykin, I. A.; Donelan, M. A.; Mellen, R. H.; McLaughlin, D. J.

Asymmetry of wind waves was studied in laboratory tank tinder varied wind and fetch conditions using both bispectral analysis of wave records and third-order statistics of the surface elevation. It is found skewness S (the normalized third-order moment of surface elevation describing the horizontal asymmetry waves) varies only slightly with the inverse wave u*/Cm (where u* is the air friction velocity and Cm is phase speed of the dominant waves). At the same time asymmetry A, which is determined from the Hilbert transform of the wave record and characterizes the skewness of the rate of change of surface elevation, increase consistently in magnitude with the ratio u*/Cm. This suggests that nonlinear distortion of the wave profile determined by the degree of wind forcing and is a sensitive indicator of wind-wave interaction processes. It is shown that the asymmetric profile of waves can described within the frameworks of the nonlinear nonspectral concept (Plate, 1972; Lake and Yuen, 197 according to which the wind-wave field can be represented as a coherent bound-wave system consisting mainly of dominant component w. and its harmonics propagating with the same speed C. , as observed by Ramamonjiaris and Coantic (1976). The phase shift between o). harmonics is found and shown to increase with the asymmetry of the waves.

Asymmetry and basic pathways in sleep-stage transitions

NASA Astrophysics Data System (ADS)

Lo, Chung-Chuan; Bartsch, Ronny P.; Ivanov, Plamen Ch.

2013-04-01

We study dynamical aspects of sleep micro-architecture. We find that sleep dynamics exhibits a high degree of asymmetry, and that the entire class of sleep-stage transition pathways underlying the complexity of sleep dynamics throughout the night can be characterized by two independent asymmetric transition paths. These basic pathways remain stable under sleep disorders, even though the degree of asymmetry is significantly reduced. Our findings demonstrate an intriguing temporal organization in sleep micro-architecture at short time scales that is typical for physical systems exhibiting self-organized criticality (SOC), and indicates nonequilibrium critical dynamics in brain activity during sleep.

What makes children with cerebral palsy vulnerable to malnutrition? Findings from the Bangladesh cerebral palsy register (BCPR).

PubMed

Jahan, Israt; Muhit, Mohammad; Karim, Tasneem; Smithers-Sheedy, Hayley; Novak, Iona; Jones, Cheryl; Badawi, Nadia; Khandaker, Gulam

2018-04-16

To assess the nutritional status and underlying risk factors for malnutrition among children with cerebral palsy in rural Bangladesh. We used data from the Bangladesh Cerebral Palsy Register; a prospective population based surveillance of children with cerebral palsy aged 0-18 years in a rural subdistrict of Bangladesh (i.e., Shahjadpur). Socio-demographic, clinical and anthropometric measurements were collected using Bangladesh Cerebral Palsy Register record form. Z scores were calculated using World Health Organization Anthro and World Health Organization AnthroPlus software. A total of 726 children with cerebral palsy were registered into the Bangladesh Cerebral Palsy Register (mean age 7.6 years, standard deviation 4.5, 38.1% female) between January 2015 and December 2016. More than two-third of children were underweight (70.0%) and stunted (73.1%). Mean z score for weight for age, height for age and weight for height were -2.8 (standard deviation 1.8), -3.1 (standard deviation 2.2) and -1.2 (standard deviation 2.3) respectively. Moderate to severe undernutrition (i.e., both underweight and stunting) were significantly associated with age, monthly family income, gross motor functional classification system and neurological type of cerebral palsy. The burden of undernutrition is high among children with cerebral palsy in rural Bangladesh which is augmented by both poverty and clinical severity. Enhancing clinical nutritional services for children with cerebral palsy should be a public health priority in Bangladesh. Implications for Rehabilitation Population-based surveillance data on nutritional status of children with cerebral palsy in Bangladesh indicates substantially high burden of malnutrition among children with CP in rural Bangladesh. Children with severe form of cerebral palsy, for example, higher Gross Motor Function Classification System (GMFCS) level, tri/quadriplegic cerebral palsy presents the highest proportion of severe malnutrition; hence, these

Cerebral Arterial Occlusion Did Not Promote the Prevalence of Cerebral Amyloid Angiopathy.

PubMed

Honda, Kazuhiro

2016-08-01

An impairment of amyloid-β (Aβ) clearance has been suggested in Alzheimer's disease. Perivascular drainage along cerebrovascular vessels is considered an important amyloid clearance pathway. This study examined the effect of reduced arterial pulsation that could cause an impairment in cerebral amyloid drainage on the prevalence of cortical microbleeds (CMBs), a surrogate marker for cerebral amyloid angiopathy (CAA). Patients who lost depiction of either side of the carotid artery or the middle cerebral artery on magnetic resonance angiography were studied. Those who showed acute cerebral infarction or a previous cortical cerebral infarction were excluded. The number of CMBs was counted on the occluded and non-occluded sides of the brain in each subject. The number of subjects who showed more CMBs on the occluded side of the brain was compared with the number of subjects who showed more CMBs on the non-occluded side of the brain. Twenty-eight patients were studied. The extent of lacunar infarction and white matter lesions was not different, irrespective of the occluded vessels or the distribution of CMBs. The prevalence of CMBs was not different between the occluded and non-occluded sides of the brain. In this cross-sectional study, reduction of arterial pulsation was not associated with a higher prevalence of CAA. Therefore, reduced arterial pulsation alone may not be enough to promote CAA.

Genetic specification of left–right asymmetry in the diaphragm muscles and their motor innervation

PubMed Central

Charoy, Camille; Dinvaut, Sarah; Chaix, Yohan; Morlé, Laurette; Sanyas, Isabelle; Bozon, Muriel; Kindbeiter, Karine; Durand, Bénédicte; Skidmore, Jennifer M; De Groef, Lies; Seki, Motoaki; Moons, Lieve; Ruhrberg, Christiana; Martin, James F; Martin, Donna M; Falk, Julien; Castellani, Valerie

2017-01-01

The diaphragm muscle is essential for breathing in mammals. Its asymmetric elevation during contraction correlates with morphological features suggestive of inherent left–right (L/R) asymmetry. Whether this asymmetry is due to L versus R differences in the muscle or in the phrenic nerve activity is unknown. Here, we have combined the analysis of genetically modified mouse models with transcriptomic analysis to show that both the diaphragm muscle and phrenic nerves have asymmetries, which can be established independently of each other during early embryogenesis in pathway instructed by Nodal, a morphogen that also conveys asymmetry in other organs. We further found that phrenic motoneurons receive an early L/R genetic imprint, with L versus R differences both in Slit/Robo signaling and MMP2 activity and in the contribution of both pathways to establish phrenic nerve asymmetry. Our study therefore demonstrates L–R imprinting of spinal motoneurons and describes how L/R modulation of axon guidance signaling helps to match neural circuit formation to organ asymmetry. DOI: http://dx.doi.org/10.7554/eLife.18481.001 PMID:28639940

7 CFR 3405.8 - Complementary project proposals.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Complementary project proposals. 3405.8 Section 3405.8 Agriculture Regulations of the Department of Agriculture (Continued) NATIONAL INSTITUTE OF FOOD AND AGRICULTURE HIGHER EDUCATION CHALLENGE GRANTS PROGRAM Program Description § 3405.8 Complementary...

7 CFR 3405.8 - Complementary project proposals.