Inverse Asymmetry Research Articles

Effect of leaflet asymmetry on the stretching elasticity of lipid bilayers with phosphatidic acid

The asymmetry of membranes has a significant impact on their biophysical characteristics and behavior. This study investigates the composition and mechanical properties of symmetric and asymmetric membranes in giant unilamellar vesicles (GUVs) made of palmitoyloleoyl phosphatidylcholine (POPC) and palmitoyloleoyl phosphatidic acid (POPA). A combination of fluorescence quantification, zeta potential measurements, micropipette aspiration, and bilayer molecular dynamics simulations are used to characterize these membranes. The outer leaflet composition in vesicles is found consistent across the two preparation methods we employed, namely electroformation and inverted emulsion transfer. However, characterizing the inner leaflet poses challenges. Micropipette aspiration of GUVs show that oil residues do not substantially alter membrane elasticity, but simulations reveal increased membrane thickness and decreased interleaflet coupling in the presence of oil. Asymmetric membranes with a POPC:POPA mixture in the outer leaflet and POPC in the inner leaflet display similar stretching elasticity values to symmetric POPC:POPA membranes, suggesting potential POPA insertion into the inner leaflet during vesicle formation and suppressed asymmetry. The inverse compositional asymmetry, with POPC in the outer leaflet and POPC:POPA in the inner one yield less stretchable membranes with higher compressibility modulus compared with their symmetric counterparts. Challenges in achieving and predicting compositional correspondence highlight the limitations of phase-transfer-based methods. In addition, caution is advised when using fluorescently labeled lipids (even at low fractions of 0.5 mol %), as unexpected gel-like domains in symmetric POPC:POPA membranes were observed only with a specific type of labeled DOPE (dioleoylphosphatidylethanolamine) and the same fraction of unlabeled DOPE. The latter suggest that such domain formation may result from interactions between lipids and membrane fluorescent probes. Overall, this study underscores the complexity of factors influencing GUV membrane asymmetry, emphasizing the need for further research and improvement of characterization techniques.

The impact of bead milling on the thermodynamics and kinetics of the structural phase transition of VO2 particulate materials and their potential for use in thermochromic glazing

The thermodynamics and kinetics of the structural phase transition from monoclinic VO 2 (M) to rutile VO 2 (R) and vice versa were studied for particulate materials obtained by bead milling of VO 2 (M) powder. Using wet bead milling, we decreased the particle size of VO 2 (M) powder from ∼1 μm to 129 nm. With progressive milling, the switching enthalpy decreased from 47 J g −1 to 29 J g −1 due to a loss of crystallinity. The switching kinetics were studied using Friedman's differential isoconversional method. The activation energy | E α | decreases with increasing difference between the actual temperature of the material and its switching temperature ( T 0 ). Furthermore, | E α | decreases with progressive milling, and kinetic asymmetry is induced. For milled particulate materials, | E α | is lower for the switch from VO 2 (R) to VO 2 (M) than for the opposite switch. For hydrothermally synthesized nanoparticles, | E α | is in the same order of magnitude, albeit with inverse switching asymmetry. Latter may result from different defects that are introduced during both preparation techniques. Applying layers of milled particulate material to glass sheets yielded thermochromic coatings with luminous transmission of 40.7% and solar modulation of 8.3%. This demonstrates that milled VO 2 particles have potential for use in energy efficient thermochromic windows. • Switching enthalpy of VO 2 particulate material decreases with progressive milling. • Activation energy of the structural phase transition decreases with particle size. • Progressive milling induces asymmetry in switching kinetics of particulate material. • Hydrothermally synthesized particles display inverse asymmetry in kinetics. • Milled VO 2 particulate materials are suited for use in thermochromic windows.

Gain-loss asymmetry in delay and effort discounting of different amounts

Loss aversion entails that people attribute greater weight to losses than to equivalent gains. In terms of discounting, it is reflected in a higher discounting rate for gains than for losses. Research on delay discounting indicates that such gain-loss asymmetry may depend on the amount of the outcome being considered. Consequently, here we address the question of how gains and losses are discounted in delay or effort conditions (physical or cognitive) across four outcome amounts. Our results replicate previous findings for intertemporal choices by showing that losses are discounted more slowly than gains, but only for smaller amounts—with no evidence of an asymmetrical evaluation for larger amounts. In physical effort discounting, we found an inverse asymmetry for the smallest amount tested (gains are discounted less steeply than losses). However, this effect was absent for larger amounts. We found no evidence to support a gain-loss asymmetry in the evaluation of gains or losses in cognitive effort. Overall, our findings indicate that loss aversion may not be as pervasive as previously expected, at least when decisions are effort-based.

Large-scale asymmetry in galaxy spin directions: evidence from the Southern hemisphere

AbstractRecent observations using several different telescopes and sky surveys showed patterns of asymmetry in the distribution of galaxies by their spin directions as observed from Earth. These studies were done with data imaged from the Northern hemisphere, showing excellent agreement between different telescopes and different analysis methods. Here, data from the DESI Legacy Survey was used. The initial dataset contains$\sim\!2.2\times 10^7$galaxy images, reduced to$\sim\!8.1\times 10^5$galaxies annotated by their spin direction using a symmetric algorithm. That makes it not just the first analysis of its kind in which the majority of the galaxies are in the Southern hemisphere, but also by far the largest dataset used for this purpose to date. The results show strong agreement between opposite parts of the sky, such that the asymmetry in one part of the sky is similar to the inverse asymmetry in the corresponding part of the sky in the opposite hemisphere. Fitting the distribution of galaxy spin directions to cosine dependence shows a dipole axis with probability of 4.66$\sigma$. Interestingly, the location of the most likely axis is within close proximity to the CMB Cold Spot. The profile of the distribution is nearly identical to the asymmetry profile of the distribution identified in Pan-STARRS, and it is within 1$\sigma$difference from the distribution profile in SDSS and HST. All four telescopes show similar large-scale profile of asymmetry.

Цільова та етична неефективність формальних правил як чинник поширення маніпулювання суспільними настроями та уповільнення інституційних реформ

The article is aimed at identifying criteria for the feasibility of reforming the formal rules with significant purposeful and ethical inefficiency in the context of spreading the practice of manipulation of social sentiment. It is found that in the structure of formal rules with purposeful or ethical inefficiency, two following components can be allocated: basic formal rules adopted to achieve a specific goal; secondary formal rules that should ensure the proper implementation of the relevant basic formal rules and compensate for their inefficiency. In the absence of manipulation of social sentiment, the main factor that causes the negative impact of formal rules with purposeful or ethical inefficiency on the dynamics of formal rules and the effectiveness of institutional reforms is an increase in the number of secondary formal rules. In contrast, in the context of the spread of the practice of manipulation of social sentiment, the main threats to the success of institutional reforms are: significant inverse asymmetry of basic formal rules; the ability of formal rules with purposeful or ethical inefficiency to independently create conditions that are favorable for the manipulation of social sentiment. It is identified that the feasibility of reforming formal rules characterized by purposeful or ethical inefficiency is determined by whether the relevant formal rules have turned into an instrument for manipulation of social sentiment: in cases where ineffective formal rules have become such an instrument, their reform becomes impractical and should be postponed until the practice of manipulation of social sentiment around issues regulated by these formal rules is eliminated. It is shown that in the context of the spread of the practice of manipulation of social sentiment, an additional criterion for the feasibility of reforming ineffective formal rules is the absence of spread of the practice of manipulation of social sentiment into a range of problems regulated by the relevant ineffective formal rules.

Feminismo y Derecho Penal

En el presente trabajo se pretende abordar cómo el feminismo ha influido en el Derecho Penal chileno, observando en primer lugar el fenómeno político del feminismo, considerando la gran fuerza que este movimiento ha tenido en Chile, para luego, en segundo lugar, observar la influencia de este movimiento en el Derecho Penal chileno. En dicho contexto, se abordarán tres reformas al Derecho Penal sustantivo de este último tiempo: La Ley sobre Interrupción Voluntaria del Embarazo, Ley Nº21.030; la Ley sobre el Femicidio, Ley Nº20.480; y la Ley sobre Acoso Sexual en Espacios Públicos, Ley Nº21.153. Como se observará, la tesis central de este trabajo es que, si bien el feminismo ha influido en el Derecho Penal, ello no ha implicado establecer una asimetría inversa, sino que una igualdad de derechos en la legislación penal entre hombres y mujeres. Finalmente, terminaré el trabajo con algunas conclusiones.

Computation of shock wave structure using a simpler set of generalized hydrodynamic equations based on nonlinear coupled constitutive relations

Generalized hydrodynamic equations were originally proposed to describe the rarefied non-equilibrium flows beyond the Navier–Stokes–Fourier (NSF) equations by constructing a non-equilibrium canonical distribution function for the mesoscopic Boltzmann equation. Subsequently, nonlinear coupled constitutive relations (NCCR) were developed under the adiabatic assumption, the Eu’s closure, and Myong’s simplification. NCCR+ was also proposed to include the omitted terms in Myong’s simplification. The goal of this paper is to assess the improvements in the accuracy due to NCCR+ and the influence of the bulk viscosity in one-dimensional steady shock wave structure for monatomic and diatomic gases. In order to solve NCCR+ equations, a coupled solution process based on the time-independent method for non-conserved variables is employed, which is different from the previous uncoupled solution process used for the NCCR equations. Shock structures in argon and nitrogen are calculated up to Mach 50, where the shock profile, inverse shock thickness, asymmetry parameter, and temperature–density separation distance are validated by DSMC and available experimental measurements. The results show that NCCR+ could not provide much improvement in accuracy compared to NCCR but adds to the computational cost, suggesting that Myong’s simplification used in NCCR is satisfactory. Both NCCR and NCCR+ perform better than NSF in computing the one-dimensional shock wave structure at high Mach numbers. It is also shown that the bulk viscosity has significant influence on the accuracy of prediction of the shock wave structure in a diatomic gas using both NSF and NCCR. Stokes’ hypothesis in conventional NSF is valid only for flows in a monatomic gas and for very low Mach number flows in a diatomic gas. Additionally, it is also found that the viscosity exponent s = 0.81 in variable-hard-sphere model provides a good fit with the experimental data for shock wave in argon using NCCR.

Analysis of the global ionospheric disturbances of the March 2015 great storm

AbstractThe global ionospheric storm in March 2015 was investigated by using data from over 3000 GPS stations worldwide. In this study, total electron content (TEC), rate of TEC (ROT), and ROT's standard deviation rate of the TEC index, as well as the second‐order difference operator TECT, were considered as main characteristic methods to distinguish ionosphereic disturbances. The results show that (1) based on the multiple methods above, we all observed that for the first time, there were three equatorward traveling ionospheric disturbances (TIDs) in the main phase of this storm. In North America, the disturbance zone expanded to ~40°N; the disturbance periods and AE peak stages were roughly synchronous. We suggest that these three TIDs were induced by the propagation of atmospheric gravity waves to low latitudes under the action of AE. (2) The most intense positive storm occurred over South America and the South Atlantic (over 300% enhancement; 00:00–05:00 UT on 18 March), whereas a negative storm was observed in the corresponding region of the Northern Hemisphere. Such inverse hemispheric asymmetry in intensity and structure can be explained by the variations of the thermospheric composition, the IMF By component, and the geomagnetic intensity. (3) On 18 March, a negative storm dominated globally (except at certain low latitudes), and tended to propagate equatorward and decay with time, which could be largely attributed to the storm circulation theory. And the evolution of the negative storm was further characterized by the foF2 variations of ionosondes.

A method for accurate pH mapping with chemical exchange saturation transfer (CEST) MRI.

Chemical exchange saturation transfer (CEST) MRI holds enormous promise for imaging pH. Whereas the routine CEST-weighted MRI contrast is complex and susceptible to confounding factors such as labile proton ratio, chemical shift, bulk water relaxation and RF saturation, ratiometric CEST imaging simplifies pH determination. However, the conventional ratiometric CEST (RCEST) MRI approach is limited to CEST agents with multiple exchangeable groups. To address this limitation, RF power-based ratiometric CEST (PRCEST) imaging has been proposed that ratios CEST effects obtained under different RF power levels. Nevertheless, due to concomitant RF saturation (spillover) effect, the recently proposed PRCEST imaging is somewhat dependent on parameters including bulk water relaxation time and chemical shift. Herein we hypothesized that RF power-based ratiometric analysis of RF spillover effect-corrected inverse CEST asymmetry (PRICEST) provides enhanced pH measurement. The postulation was verified numerically, and validated experimentally using an in vitro phantom. Briefly, our study showed that the difference between MRI-determined pH (pHMRI ) and electrode-measured pH being 0.12 ± 0.13 and 0.04 ± 0.03 for PRCEST and PRICEST imaging, respectively, and the newly proposed PRICEST imaging provides significantly more accurate pH determination than PRCEST imaging (P < 0.01, Wilcoxon signed-rank test). Notably, the exchange rate shows dominantly base-catalysed relationship with pH, independent of creatine concentration (P > 0.10, Analysis of Covariance). In addition, the derived labile proton ratio linearly scales with creatine concentration (P < 0.01, Pearson Regression). To summarize, PRICEST MRI provides concentration-independent pH imaging, augmenting prior quantitative CEST methods for accurate pH mapping. Copyright © 2015 John Wiley & Sons, Ltd.

Geomorphic imprints of repeated tsunami waves in a coastal valley in northeastern Japan

Devastating tsunami waves induced by the 2011 off the Pacific coast of Tohoku Earthquake severely inundated valleys along the ria-type (notched rocky) coast in northeastern Japan, causing erosion of bedrock on valley-side slopes. Using high-resolution topographic data obtained by terrestrial and airborne laser scanning, we investigated detailed morphology of the eroded valley in a typical site at Aneyoshi. We found several characteristic features likely affected by tsunami wave erosion: 1) a series of small cliffs on the valley-side slopes related to the tsunami flow depth, 2) an inverse asymmetry of side slopes at ingrown meander bends, 3) an exceptionally wide valley bottom near the coast, and 4) a knickpoint located around the maximum tsunami run-up point far back from the coast. These topographic features are ascribable to repeated tsunami wave erosion since the mid-Holocene.

Quantitative chemical exchange saturation transfer (qCEST) MRI - omega plot analysis of RF-spillover-corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate.

Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST-weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P < 0.01) while the pH-dependent exchange rate followed a dominantly base-catalyzed exchange relationship (P < 0.01). In summary, our study verified that a simplified qCEST analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system.

Model for a Brownian ratchet with improved characteristics for particle separation

We introduce an extension of the simple on-off ratchet by including a second asymmetric sawtooth potential with half the periodicity and inverse asymmetry in the ratchet cycle. As a result of this additional potential, the Brownian particles exhibit reversal of the direction of their mean displacement when relevant parameters such as the on time of the potentials are varied. This direction reversal offers new opportunities for microfluidic particle separation in sieve devices. Based on the results of our extended ratchet model, we propose two designs. Compared to the classical microfluidic sieve, the proposed devices can be made of significantly smaller sizes without sacrificing the resolution of the separation process. In fact, one of our devices can be reduced to a single channel. We study our extended ratchet model by Brownian dynamics simulations and derive analytical and approximative expressions for the mean displacement using an extension of the method of discrete steps. We show that these expressions are valid in relevant regions of the parameter space and that they can be used to predict the occurrence of direction reversal.

Asymmetry in reproductive isolation and its effect on directional mitochondrial introgression in the parapatric ground beetles Carabus yamato and C. albrechti

AbstractSpeciation studies seek to clarify the origin of reproductive isolation, the various mechanisms working from mate recognition through postzygotic stages. Asymmetric effects of isolating barriers can result in asymmetrical gene introgression during interspecific hybridization. The flightless ground beetles Carabus yamato and C. albrechti are distributed parapatrically in Japan, showing repeated asymmetrical introgression of mitochondria from C. albrechti to C. yamato. This pattern suggests that reproductive isolation between these species is strong, but incomplete and asymmetric (i.e., weaker for the cross between a C. albrechti female and a C. yamato male). To test this hypothesis, we conducted interspecific mating experiments in the laboratory. The estimates of total reproductive isolation, which occurred mainly at the premating and postmating/prezygotic stages, were high (isolation index = 0.964 for C. yamato female × C. albrechti male and 0.886 for the reciprocal cross), supporting the hypothesis of strong, but incomplete isolation. However, the observed difference between the reciprocal crosses was not sufficiently large to conclude that it caused directional introgression of mitochondria. Instead, we found asymmetry in individual isolating barriers in the postmating/prezygotic stages that coincided with the prediction, perhaps resulting from morphological mismatch of heterospecific genitalia. Although this asymmetry was compensated for by an inverse asymmetry of isolation in the postzygotic stage, the contribution of these individual barriers to total isolation may change for our expectation when considering females mating with multiple heterospecific males.

Polarization factors in the general case of three-wave diffraction

The polarization properties of diffracted radiation depending on the geometry of three-wave configurations and spectral and polarization states of the incident radiation are considered on the basis of the representation of multiple diffraction geometry in the natural crystallographic coordinates. The analytical expressions, obtained earlier for the symmetric cases [Sheludko (2004). Acta Cryst. A60, 281-282], are extended for the general case of three-wave diffraction of radiation on single crystals. The problem of the description of conditions of inverse asymmetry of three-wave diffraction profiles is reduced to a classical analysis of quadratic and cubic equations.

Hypercalculia in Savant Syndrome: Central Executive Failure?

Background The existence of outstanding cognitive talent in mentally retarded subjects persists as a challenge to present knowledge. We report the case of a 16-year-old male patient with exceptional mental calculation abilities and moderate mental retardation. Methods The patient was clinically evaluated. Data from standard magnetic resonance imaging (MRI) and two 99mTc-ethyl cysteine dimer (ECD)-single photon emission computer tomography (SPECT) (in resting condition and performing a mental calculation task) studies were analyzed. Results Main neurologic findings were brachycephalia, right-side neurologic soft signs, obsessive personality profile, low color-word interference effect in Stroop test, and diffuse increased cerebral blood flow during calculation task in 99mTc-ECD SPECT. MRI showed anatomical temporal plane inverse asymmetry. Conclusions Evidence appears to support the hypothesis that savant skill is related to excessive and erroneous use of cognitive processing resources instigated by probable failure in central executive control mechanisms.

Human primary auditory cortex in women and men

Specific patterns of anatomical symmetry or asymmetry have been associated with sex differences in human brain structure and function. An observer-independent cytoarchitectonic method for the quantification of cell volume densities and areal borders was used to investigate the size and microstructure of primary auditory cortex (Brodmann area 41) in female (n = 14) and male (n = 13) postmortem brains. The total brain volume-adjusted volume of the primary auditory cortex was significantly larger in women than in men bilaterally. Inverse asymmetry towards the right side, as opposed to well-known asymmetries towards the left side, was more frequent in women. Laminar cell volume densities of BA 41 showed no gender effect. The morphometric data confirm (in part) gender differences in the cerebral organization of primary auditory cortex.

The relation between asymmetry and amplitude of the P300 field in schizophrenia

Objectives: A general reduction of auditory P300 amplitude is one of the most consistently replicated observations in schizophrenic patients. However, a left hemisphere amplitude reduction is discussed controversely.Methods: Encouraged by this controversy we analysed P300 data of 53 controls and 60 patients of the schizophrenia spectrum (ICD-10: F20, F23, F25).Results: Our main result was the finding of the correlation between general amplitude and hemispheric asymmetry in the patient group: low general amplitudes were assigned to a left hemispheric amplitude reduction, high amplitudes to a right hemispheric reduction. Based on this result, we grouped all subjects according to their hemispheric asymmetry pattern. The control group and the group of schizoaffective patients (F25) with a left hemispheric amplitude reduction showed the inverse asymmetry pattern of P300 amplitude compared to subjects with a right hemispheric amplitude reduction. In contrast, the schizophrenic patients (F20) showed only a difference in P300 amplitudes measured at electrode sites of the left hemisphere. Additionally, we could show, that the amount of the general amplitude reduction in patients was different between the diagnostic groups.Conclusions: We conclude that a left hemispheric amplitude reduction is not a general feature of schizophrenia but it seems to be pathological when combined with a general amplitude reduction.

Asymmetry of basal ganglia glucose metabolism and dopa responsiveness in parkinsonism.

We investigated, by positron emission tomography (PET) with [18F]fluoro-2-deoxy-d-glucose (FDG) (FDG-PET), brain glucose metabolism in 19 patients with parkinsonian features. We compared local pattern of FDG uptake and asymmetry indexes in patients with therapeutic response to levodopa (L-dopa) (group 1, presumed Parkinson's disease, n = 9) and patients without L-dopa therapeutic response (group 2, presumed striatonigral degeneration, n = 10). Limb dystonia was present in 11% of patients in group 1 and in 40% of patients in group 2. Asymmetry in basal ganglia metabolism was distributed differently in the two groups (analysis of variance, p < 0.04). In superior and inferior putamen, superior and middle caudate, ventral striatum, and inferior thalamus, relative reduction in metabolism on the side contralateral to predominant parkinsonian signs was associated with L-dopa unresponsiveness. On the contrary, in middle caudate, ventral striatum, and inferior thalamus, a relative increase in metabolism on the side contralateral to the predominant side, parkinsonian signs were found in L-dopa-responsive patients. Our FDG-PET study using simple statistical procedures demonstrates inverse asymmetry of basal ganglia glucose metabolism in parkinsonian patients grouped on the sole basis of L-dopa responsiveness.

Individualism-Collectivism and Global Self-Esteem

How does the cultural construct of individualism-collectivism relate to global self-esteem? It is proposed that highly collectivist cultures promote the development of one dimension of global self-esteem (generalized self-liking) but challenge the development of the other (generalized self-competence), whereas highly individualist cultures are characterized by the inverse asymmetry. This cultural trade-off hypothesis was investigated by comparing a sample of 302 Chinese with a sample of 343 American college students. The cross-cultural equivalence of the two-dimensional model of self-esteem was first assessed and found to be adequate. Given the high intercorrelation of the 2 self-esteem dimensions, only the unique or non-common part of each dimension was used in hypothesis testing. As predicted, the Chinese were lower in self-competence but higher in self-liking than the Americans. Caveats and implications are discussed.

A role of the striatum in premotor cortical seizure development

Striatal function in partial seizure development induced by low frequency cortical stimulation of the ipsilateral premotor cortex was investigated by either electrolytic lesion placement or microinjection of putative neurotransmitter-related drugs into the ipsilateral striatum. Unilateral striatal lesioning and intrastriatal injection of muscimol, a GABA-agonist, and glutamic acid diethylester, a presumed antagonist for glutamatergic neurotransmission, were effective in suppressing seizure development, whereas intrastriatal injection of a subconvulsive dose of carbamylcholine chloride (carbachol), a cholinergic agonist, decreased the seizure threshold. In contrast to the ipsilaterally dominant metabolic activation in the intact animal, an inverse asymmetry due to a considerable reduction of deoxyglucose uptake in the ipsilateral thalamus, entopeduncular nucleus, substantia nigra, striatum and surrounding cortex of the focus was found in those brains with striatal lesion. Altogether, the findings suggest that experimental reduction of the inhibitory striatal outputs to both the entopeduncular nucleus and the substantia nigra enhances tonic activities of the projection GABAergic neurons in those nuclei, thereby inhibiting seizure development.