Asymmetry In Region Research Articles

Behavioral Differences in the Upper and Lower Visual Hemifields in Shape and Motion Perception

Perceptual accuracy is known to be influenced by stimuli location within the visual field. In particular, it seems to be enhanced in the lower visual hemifield (VH) for motion and space processing, and in the upper VH for object and face processing. The origins of such asymmetries are attributed to attentional biases across the visual field, and in the functional organization of the visual system. In this article, we tested content-dependent perceptual asymmetries in different regions of the visual field. Twenty-five healthy volunteers participated in this study. They performed three visual tests involving perception of shapes, orientation and motion, in the four quadrants of the visual field. The results of the visual tests showed that perceptual accuracy was better in the lower than in the upper visual field for motion perception, and better in the upper than in the lower visual field for shape perception. Orientation perception did not show any vertical bias. No difference was found when comparing right and left VHs. The functional organization of the visual system seems to indicate that the dorsal and the ventral visual streams, responsible for motion and shape perception, respectively, show a bias for the lower and upper VHs, respectively. Such a bias depends on the content of the visual information.

The morphostructure of the South Atlantic Ridge in the Tristan da Cunha hot spot area

Investigation of the rift zone and flanks of the South Atlantic midoceanic ridge in the Tristan da Cunha hot spot area revealed that their morphostructure is atypical of slow spreading ridges. Feeding the spreading center with magmatic material, the hot spot changes the morphology of the axial zone and transform faults. It itself forms a relief ensemble that differs from the rift one as well. The continuous migration of the spreading center in the westerly direction stimulates the formation of a spacious volcanic highland, which is responsible for the regional asymmetry of ridge flanks in its extended segments (hundreds kilometers long).

Patterns of directional asymmetry in the pelvis and pelvic canal

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.

Morphological asymmetries of mouse brain assessed by geometric morphometric analysis of MRI data

Mammalian brain has repeated structures at both sides of the median plane, although some asymmetries have been described even under normal conditions. Characterizing normal patterns of asymmetry in mouse brain is important to recognize features that depart from expected ranges in the most widely used mammalian model. Analyses on brain morphology based on magnetic resonance image (MRI) have largely focused on volumes while less is known about shape asymmetry. We introduce a flexible protocol based on geometric morphometrics to assess patterns of asymmetry in shape and size of mouse brain from microMRI scans. After systematic digitization of landmarks and semilandmarks, we combine multivariate methods for statistical analyses with visualization tools to display the results. No preliminary treatment of the images (e.g. space normalization) is needed to collect data on MRI slices and visual representations improve the interpretation of the results. Results indicated that the protocol is highly repeatable. Asymmetry was more evident for shape than for size. Particularly, fluctuating asymmetry accounted for more variation than directional asymmetry in all brain regions. Since this approach can detect subtle shape variation between sides, it is a promising methodology to explore morphological changes in the brain of model organisms and can be applied in future studies addressing the effect of genetic and environmental factors on brain morphology.

New Palpable Breast Lump With Recent Negative Mammogram: Is Repeat Mammography Necessary?

The purpose of this article is to determine the utility of repeat mammography, compared with targeted ultrasound and previous mammogram, in the assessment of an interval palpable breast lump found within 1 year after a negative mammogram study. Women who were examined for a new palpable lump with mammography and targeted ultrasound between January 2005 and December 2012, who also had a negative mammogram within the previous 6-12 months, were included. The following data were collected: age, mammographic findings, change from previous mammogram, ultrasound findings, BI-RADS category, and biopsy results. A total of 618 palpable lumps in 612 women (mean [± SD] age, 55.9 ± 11.2 years) were included in this study. In 314 of 618 cases (50.8%), a sonographic finding or mammographic change, or both was detected in the region of the palpable lump. Ultrasound detected a finding in 311 cases (50.3%), whereas repeat mammography detected a change in only 80 (12.9%) cases (p < 0.001). Of the 314 cases with imaging findings, 234 findings (74.5%) were detected by ultrasound alone. Repeat mammography identified a more prominent focal asymmetry in the palpable region in three cases with no sonographic correlate; none had malignancy. Eighty lesions were biopsied, and 48 (60.0%) of them were positive for malignancy. The repeat mammogram findings were unchanged for 10 of these lesions. Interval palpable breast lumps should be evaluated with targeted ultrasound. Mammography does not appear to add value beyond sonography performed by trained ultrasound technologists and should not be routinely performed.

Prevalence of anaemia and iron deficiency in Portugal: the EMPIRE study.

Anaemia and iron deficiency are major public health problems with great implications on quality of life. To establish the general prevalence of anaemia and iron deficiency in the adult Portuguese population and the prevalence by age, gender and region. This was a population-based, cross-sectional study (EMPIRE study) based on a representative sample of 7980 adults residing in mainland Portugal, which were selected using a random route sampling method. Levels of haemoglobin, ferritin, creatinine and C-reactive protein were measured by Point-of-Care assays; participants also completed a questionnaire about demography and medical history. The measured prevalence of anaemia was 19.9% (95% confidence interval: 19.0-20.8%); 84% of cases were previously undiagnosed. Anaemia was more prevalent among women (20.8%), young adults (18-34 years) (22.8-30.5%), older adults (21.0%), and pregnant women (54.2%). Anaemia varied across regions: from 15.5% in the Center region to 24.9% in the South. Iron deficiency was also highly prevalent: 16.7% (ferritin <15 ng/mL), 31.9% (<30 ng/mL), 53.3% (<50 ng/mL) and 84.3% (<100 ng/mL). Iron deficiency anaemia represented most anaemia cases: 29.0% (ferritin <15 ng/mL), 54.8% (<30 ng/mL), 75.4% (<50 ng/mL) and 92.5% (<100 ng/mL). Anaemia and iron deficiency are highly prevalent in Portugal and largely undiagnosed. Women, young adults and older individuals are more prone to present these conditions and there are marked regional asymmetries. Nationwide strategies for prevention, diagnosis and treatment of these conditions should be implemented.

Measurement of the charge asymmetry in highly boosted top-quark pair production in s=8 TeV pp collision data collected by the ATLAS experiment

In the $pp \rightarrow t\bar{t}$ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb$^{-1}$ of $pp$ collision data at $\sqrt{s} =$ 8 TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair ($m_{t\bar{t}} > $ 0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within $-$2 $ < |y_t| - |y_{\bar{t}}| <$ 2 is measured to be 4.2 $\pm$ 3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three $t\bar{t}$ mass bins is also presented.

Sex differences in behavioural and neural responsiveness to mate calls in a parrot.

Vocalisation in songbirds and parrots has become a prominent model system for speech and language in humans. We investigated possible sex differences in behavioural and neural responsiveness to mate calls in the budgerigar, a vocally-learning parrot. Males and females were paired for 5 weeks and then separated, after which we measured vocal responsiveness to playback calls (a call of their mate versus a call of an unfamiliar conspecific). Both sexes learned to recognise mate calls during the pairing period. In males, but not females, mate calls evoked significantly fewer vocal responses than unfamiliar calls at one month after separation. Furthermore, in females, there was significantly greater molecular neuronal activation in response to mate calls compared to silence in the caudomedial mesopallium (CMM), a higher-order auditory region, in both brain hemispheres. In males, we found right-sided dominance of molecular neuronal activation in response to mate calls in the CMM. This is the first evidence suggesting sex differences in functional asymmetry of brain regions related to recognition of learned vocalisation in birds. Thus, sex differences related to recognition of learned vocalisations may be found at the behavioural and neural levels in avian vocal learners as it is in humans.

Sub-national fiscal policy under cooperative and non-cooperative models

This article presents a comparative analysis of the optimal fiscal response to shocks in the sub-national public sector in cooperative and non-cooperative models. The analysis is undertaken by comparing models that assume idiosyncratic demandside shocks and sub-national autonomy to collect taxes, with models that assume that the central government collects the taxes of the whole country and redistributes them across regions. Results show that under symmetrical conditions, the non-cooperative solution may result in greater stabilization and lower sub-national public expenditure than the cooperative solution. However, if regional asymmetries are introduced into the model, results may be reversed.

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

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

Международная образовательная миграция: региональный аспект

The article provides a profound analysis of the main trends of international student migration for tertiary education, discusses the key factors influencing the choice of destination for studying abroad, and reveals the regional peculiarities of instruments for student migration regulation. The first part of the paper highlights the official statistics showing that in recent decades the world witnessed the steady increase in the number of international students, concentrating mainly in the USA and the European Union. Almost 48% of all international students in the world study in the European Union. This region also shows the highest internal student mobility. Among others, such countries as Austria, Luxemburg, Switzerland, Australia and New Zealand demonstrate the biggest shares of foreign students in the total number of university students. As for donor countries, the dynamics proves the major role of the Asia region, with a half of all international students originated from it. The largest number of foreign students come from China, India and South Korea. Nonetheless, the Asia region becomes a popular destination of student mobility nowadays. The second part of the article concerns different coordination policies of tertiary migration in the regional context. Mostly in developed countries, practices of attracting foreign students to study in professional programs and degree programs with a perspective to enter a national labor market after graduation become more and more popular. Postgraduate migration remains a priority. Most countries encourage job-searching for foreign graduate students, as they are considered to have a high-skill level, international views and an opportunity to live and work in a variety of socio-cultural conditions. Further analysis refers to the main factors determining the choice of destination for foreign students, which are: geographical proximity, language skills, cultural proximity, the cost of education, and a country's reputation in the field of higher education. The paper reveals the leading role of the EU in the developed intraregional educational mobility, the regional asymmetry of migration processes in other regions of the world, and Asian countries actively promoting temporary educational and labor migration to developed countries with incentives to return to a home-country in the future. In recent years, due to positive dynamics of the return migrants number, an interest in the creation of the returnees strategy grows as well as desire of developed and developing countries to benefit most from the return migration.

TERRITORIAL DISTRIBUTION OF REGIONAL SCIENCE PROGRAMS IN BRAZIL

The heterogeneous form of occupation of the Brazilian territory is reproduced in the distribution of higher education supply in the country. Taking as a premise that higher education institutions as well as regional science are catalysts for development, the aim of this paper is to discuss the territorial stricto sensu courses of local/regional development in Brazil. The research is characterized as exploratory, quantitative approach with document design. The analysis showed the presence of uneven regional science graduate programs in Brazil, with the highest concentration in the South and Southeast regions and with a predominance of the institutions, which denotes the repetition of Brazilian regional asymmetries in higher education setting.

Relation Between Frontal Alpha Asymmetry and Anxiety in Young Patients with Generalized Anxiety Disorder.

Frontal alpha asymmetry (the relative difference in power between two signals in different hemispheres) has been suggested as biomarker for anxiety. The goal of this study was to evaluate alpha asymmetry in the frontal region for young people (7-18 years) with generalized anxiety disorder, diagnosed according to two statistic manuals (DMS-IV-R and ICD-10), the medical history and the neuropsychological assessment. The QEEG recording and analysis of the obtained results from alpha spectra power and log of alpha spectra power are made in four conditions (eyes open, eyes closed, VCPT and ACPT). The obtained results for alpha power in general showed higher cortical activity in the right hemisphere, associated with negative emotions. The calculated alpha asymmetry separate for eyes open, eyes closed, VCPT and ACPT conditions showed the right activation in all four conditions. In addition, the right frontal asymmetry was specific for the Fp(1)-Fp(2) region, while a greater left frontal activation was recorded for the F(7)-F(8) region. The log of alpha power in general was additionally analyzed. The calculated asymmetry score in general (in a way that the left log transformed score was subtracted from the right) confirmed a greater right activation. Testing the power of the whole alpha band (μV(2)) in general, for all four conditions and for frontal region confirmed the right alpha asymmetries in all participants. The right alpha asymmetry in the frontal region was specific only for the Fp(1)-Fp(2) region (frontopolar region). The only greater left frontal activation was registered between the F(7)-F(8) region. Our findings are supported by many other studies using specific localization methods like fMRI or LORETA source localization.

Observation of droplet soliton drift resonances in a spin-transfer-torque nanocontact to a ferromagnetic thin film

Magnetic droplet solitons are non-linear dynamical modes that can be excited in a thin film with perpendicular magnetic anisotropy with a spin-transfer-torque. Although droplet solitons have been proved to be stable with a hysteretic response to applied currents and magnetic fields at low temperature, measurements at room temperature indicate less stability and reduced hysteresis width. Here, we report evidence of droplet soliton drift instabilities, leading to drift resonances, at room temperature that explains their lower stability. Micromagnetic simulations show that the drift instability is produced by an effective field asymmetry in the nanocontact region that can have different origins.

Atypically rightward cerebral asymmetry in male adults with autism stratifies individuals with and without language delay.

In humans, both language and fine motor skills are associated with left‐hemisphere specialization, whereas visuospatial skills are associated with right‐hemisphere specialization. Individuals with autism spectrum conditions (ASC) show a profile of deficits and strengths that involves these lateralized cognitive functions. Here we test the hypothesis that regions implicated in these functions are atypically rightward lateralized in individuals with ASC and, that such atypicality is associated with functional performance. Participants included 67 male, right‐handed adults with ASC and 69 age‐ and IQ‐matched neurotypical males. We assessed group differences in structural asymmetries in cortical regions of interest with voxel‐based analysis of grey matter volumes, followed by correlational analyses with measures of language, motor and visuospatial skills. We found stronger rightward lateralization within the inferior parietal lobule and reduced leftward lateralization extending along the auditory cortex comprising the planum temporale, Heschl's gyrus, posterior supramarginal gyrus, and parietal operculum, which was more pronounced in ASC individuals with delayed language onset compared to those without. Planned correlational analyses showed that for individuals with ASC, reduced leftward asymmetry in the auditory region was associated with more childhood social reciprocity difficulties. We conclude that atypical cerebral structural asymmetry is a potential candidate neurophenotype of ASC. Hum Brain Mapp 37:230–253, 2016. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Flow past a moderately heated horizontal cylinder at low Reynolds number

Flow past a heated two-dimensional cylinder in the laminar regime is investigated. A hybrid finite element–finite volume method is used to solve Navier–Stokes and energy equations. The vortex shedding frequency defined nondimensionally as Strouhal number is observed to be increasing with heating. Vortex shedding behind heated cylinder exhibits asymmetry in wake region due to stable and unstable density stratification below and above the cylinder, respectively. A negative lift is generated due to heating, in an otherwise symmetric zero time-averaged lift configuration, due to skewness in vortex shedding towards the direction of buoyancy. We also note that the heating brings down the drag for the cases considered here. The thermal energy transport due to convection, defined by nondimensional Nusselt number is found to increase only marginally with cylinder heating.

A self-consistent phase-field approach to implicit solvation of charged molecules with Poisson-Boltzmann electrostatics.

Dielectric boundary based implicit-solvent models provide efficient descriptions of coarse-grained effects, particularly the electrostatic effect, of aqueous solvent. Recent years have seen the initial success of a new such model, variational implicit-solvent model (VISM) [Dzubiella, Swanson, and McCammon Phys. Rev. Lett. 96, 087802 (2006) and J. Chem. Phys. 124, 084905 (2006)], in capturing multiple dry and wet hydration states, describing the subtle electrostatic effect in hydrophobic interactions, and providing qualitatively good estimates of solvation free energies. Here, we develop a phase-field VISM to the solvation of charged molecules in aqueous solvent to include more flexibility. In this approach, a stable equilibrium molecular system is described by a phase field that takes one constant value in the solute region and a different constant value in the solvent region, and smoothly changes its value on a thin transition layer representing a smeared solute-solvent interface or dielectric boundary. Such a phase field minimizes an effective solvation free-energy functional that consists of the solute-solvent interfacial energy, solute-solvent van der Waals interaction energy, and electrostatic free energy described by the Poisson-Boltzmann theory. We apply our model and methods to the solvation of single ions, two parallel plates, and protein complexes BphC and p53/MDM2 to demonstrate the capability and efficiency of our approach at different levels. With a diffuse dielectric boundary, our new approach can describe the dielectric asymmetry in the solute-solvent interfacial region. Our theory is developed based on rigorous mathematical studies and is also connected to the Lum-Chandler-Weeks theory (1999). We discuss these connections and possible extensions of our theory and methods.

New Zealand regional house prices and macroeconomic shocks

A two-part SVAR model for New Zealand (NZ) identifies impacts of common macroeconomic shocks on national and regional city house prices. Results suggest that NZ regional housing market asymmetries exist in terms of responses to, as well as the relative importance of, shocks to key macroeconomic variables. Interest rate and GDP shocks in particular have significant effects on national and city house prices some 5 years later, although responses to the range of identical shocks vary in magnitude and relative importance across cities. This implies that national policies enacted to dampen/stimulate economic activity will impact differently on regional housing markets.

CPviolation: Dalitz interference,CPT, and final state interactions

Resonances and final state interactions (FSI) play a role in the formation of CP violation (CPV) constrained by CPT invariance. We provide a general formulation of CPV including resonances and FSI starting from the CPT constraint. Our discussion is elaborated within a simple $B$ decay model with the $\rho$ and $f_0(980)$ resonances plus a non resonant background including the $\pi\pi \to KK$ coupled amplitude. We consider few illustrative examples to show the interference patterns appearing in the CP asymmetry, namely, that from the $\rho$ resonance plus a non-resonant amplitude, and that from the interference of the $\rho$ and $f_0(980)$ resonances. We perform the fit of the CP asymmetry for the charmless three-body $B^\pm$ decay channel $B^{\pm}\to \pi^{\pm} \pi^+\pi^-$ and obtain as outcome the $B^{\pm}\to \pi^{\pm} K^+K^-$ for $\pi\pi$ channel asymmetry in the mass region below $1.6$ GeV in fair agreement with the new data LHCb data. Analogously, we also describe the CP asymmetry of the $B^\pm\to K^\pm\pi^+\pi^-$ decay, with that from the $B^\pm\to K^\pm K^+K^-$ channel obtained as output. As in the previous case, we also found agreement with LHCb experimental data.

Improved delayed detached-eddy simulation of massive separation around triple cylinders

The massively separated flow past triple cylinders (TriC) in tandem arrangement is simulated using the improved delayed detached-eddy simulation (IDDES) method based on the shear stress transport (SST) model, coupled with the high order adaptive dissipation scheme. The spacing between adjacent cylinders is sub-critical (1.435D). IDDES prediction of two cylinders (TC) with the same spacing is compared to experimental data for validation, and the numerical results agree well with the available measurements, except for the asymmetry in the gap region. The flow past TriC is investigated using the same method. Generally, the mean flow quantities past TriC, such as the velocity, pressure, and vorticity, are similar to the corresponding components of TC. However, the pressure fluctuations on the TriC surface are uniformly larger than those on TC. Meanwhile, the instantaneous flows past TriC are much more complex. The periodical blockage in the first gap region is found in the TriC case and leads to the up-and-down movement of shear layer in the second gap region. The tandem cylinders arrangement is proposed as the simplified landing gear geometry for the study of flow interaction and aeroacoustics, which involves complicated flow phenomena and interactions. The improved delayed detached-eddy simulation (IDDES) has shown the considerable promise of hybrid RANS/LES methods in accurate numerical prediction of the massively separated and highly unsteady turbulent flow, providing visually detailed flow structures, quantitative insight into the mechanism of unsteady flow phenomena, and precise sound sources for noise prediction.