BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological s...BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies.展开更多
This paper seeks to highlight the macroeconomic asymmetries and social impacts among eurozone countries which occurred during the time of the financial crisis,emphasising the urgent need to revise the framework of eco...This paper seeks to highlight the macroeconomic asymmetries and social impacts among eurozone countries which occurred during the time of the financial crisis,emphasising the urgent need to revise the framework of economic governance.The analysis focuses on the growing macroeconomic and social imbalances on a representative sample of selected eurozone member-states(Euro(€)North and Euro(€)South)which had posed a threat to economic sustainability and social coherence.展开更多
Two factorization approaches have been proposed for single transverse spin asymmetries. One is the cofiinear factorization, the other is the transverse-momentum-dependent factorization. They have been previously deriv...Two factorization approaches have been proposed for single transverse spin asymmetries. One is the cofiinear factorization, the other is the transverse-momentum-dependent factorization. They have been previously derived in a formal way by using diagram expansion at hadron level. If the two factorizations hold or can be proven, they should also hold when we replace hadrons with patton states. We examine these two factorizations at patton level with massless partons. It is nontrivial to generate these asymmetries at parton level with massless patrons because the asymmetries require helicity-flip and nonzero absorptive parts in scattering amplitudes. By constructing suitable patton states with massless partons we derive the two factorizations for the asymmetry in Drell-Yan processes. It is found from our results that the collinear factorization derived at parton level is not the same as that derived at hadron level. Our results with massless partons confirm those derived with single massive parton state in our previous works.展开更多
Forced geostrophic turbulence on the surface of a rotating sphere (so called β-plane turbulence) is simulated trough the use of the β-SQG+1 numerical model. Domain occupied by the fluid has a channel geometry with 5...Forced geostrophic turbulence on the surface of a rotating sphere (so called β-plane turbulence) is simulated trough the use of the β-SQG+1 numerical model. Domain occupied by the fluid has a channel geometry with 512 by 256 grid points, periodic boundary conditions in x-direction and rigid boundaries in y-direction. Random forcing is applied at high wave-numbers in the spectral space. To better understand eddies dynamics we simulate both regimes, with and without stochastic forcing, starting from identical initial conditions. Direct numerical simulations exhibit different dynamical properties in different regimes. In the freely evolving case, a wave term that competes with inertia on large-scales (added as a result of the β-effect) produces high meridional asymmetries in the eddies spatial and time scales. This asymmetry is added to the standard for the β-plane turbulence zonal asymmetry. In the forced regime there is not only anisotropy in the eddies deformation radius, but also in their orientation. The preferred direction for the warm anomalies elongation is north-western, while for the cold anomalies is north-eastern. These results may explain the observed meridional meandering of the mid-latitude zonal jets.展开更多
An analysis of the monetary synchronization of the Union of South American Nations （UNASUR） for the decade 2004 through 2013 has been conducted using the optimum currency area （OCA） theories in order to evaluate t...An analysis of the monetary synchronization of the Union of South American Nations （UNASUR） for the decade 2004 through 2013 has been conducted using the optimum currency area （OCA） theories in order to evaluate the economic integration. By applying Bayoumi and Eichengreen＇s equation, it was found that with a decent adjustment, a high percentage of countries show a tendency to harmonize their currencies in function of the four independent variables： output disturbances, the dissimilarity in exports composition, the trade linkages, and the size of the economies. To extend the model, mobility of labor and level of the integration in good＇s market were added by modifying Behrens＇ proposal, founding that the six variables are indeed related to the exchange rate harmonization at different significant levels, with a considerable moderate fitting. Additionally an analysis of variance （ANOVA） has been considered in order to study the following economic indicators： gross domestic product （GDP）, population, GDP per capita, exports to group vs. total exports, unemployment, and inflation rates so as to visualize the economic asymmetries of the Union, for the same period. Differences were inferred for all of them but not for their annual speed of change. The least significant differences （LSD） provide further results and Duncan＇s multiple range tests lead to defining groups of countries with similar characteristics.展开更多
Using the form factors calculated both in lattice QCD and HQET, we analyze the branching ratio, doublelepton polarization asymmetries and averaged double-lepton polarization asymmetries of Λ_b →Λμ^+μ^- decay in t...Using the form factors calculated both in lattice QCD and HQET, we analyze the branching ratio, doublelepton polarization asymmetries and averaged double-lepton polarization asymmetries of Λ_b →Λμ^+μ^- decay in the2 HDM Ⅲ, respectively. Combining the experimental constrains on the 2HDM Ⅲ parameters, we take two set of representative parameter spaces in our calculations. For the branching ratio of Λ+b →Λμμ-decay, considering the uncertainties of the form factors and input parameters, we find the results of both SM and 2HDM Ⅲ can satisfy the current experimental data in the framework of lattice QCD, but not in HQET. Then we calculate the double-lepton polarization asymmetries Pij and their averaged values Pij, we find the double-lepton polarization asymmetries PLT,PNN, and PTT are sensitive to the 2HDM Ⅲ. However, PLN, PNL, PNT, and PTN show the opposite results. The contribution of the 2HDM Ⅲ to their averaged values have similar results.展开更多
The physical processes associated with changes in the convective structure of an idealized tropical cyclone （TC） during landfall on a beta-plane were studied using the fifth-generation Pennsylvania State University-...The physical processes associated with changes in the convective structure of an idealized tropical cyclone （TC） during landfall on a beta-plane were studied using the fifth-generation Pennsylvania State University- National Center for Atmospheric Research Mesoscale Model, version 3 （MM5）. The simulation results suggested that the suppression of moisture supply and increased friction acted to enhance the convection from the left and front quadrants of the TC to the front and right of the TC during different periods of landfall. When surface moisture flux was turned off, convection in other parts of the quadrant was clearly suppressed and the total rainfall was reduced. When surface friction was increased, precipitation showed a marked increase after the TC made landfall. Wetter air at low and intermediate levels, and drier air at high levels around the onshore side of the coastline led to a high value of convective available potential energy （CAPE）. Consequently, convection was enhanced immediately downstream of this area when the surface moisture flux was cut off. When surface friction was increased, the physical process was similar prior to landfall. After landfall, increased convergence at the onshore side of the land resulted in enhanced convection in front of the TC. Consistent with previous findings, our results suggest that during landfall the TC structure changes from one of thermodynamic symmetry to asymmetry due to differential moisture flux between the land and sea surface. The asymmetry of the thermodynamic structure, which can be explained by the distribution of CAPE, causes an asymmetric rainfall structure.展开更多
The most powerful method to diagnose the velocity field in solar flare atmosphere isspectral analyses. That is to analyse the asymmetry and the Doppler shift of flare spectralline profiles. Recent observations indicat...The most powerful method to diagnose the velocity field in solar flare atmosphere isspectral analyses. That is to analyse the asymmetry and the Doppler shift of flare spectralline profiles. Recent observations indicated that at the impulsive phase of flares thereare obvious red asymmetry of Hα profiles and a downward velocity of 40-100km/s展开更多
We study the decays ofΛb→Λ(→pπ^(−))ℓ^(+)ℓ^(−)withℓ=(e,μ,τ).We examine the full angular distributions with polarizedΛb,where the T-odd observables are identified.We discuss the possible effects of new physics(N...We study the decays ofΛb→Λ(→pπ^(−))ℓ^(+)ℓ^(−)withℓ=(e,μ,τ).We examine the full angular distributions with polarizedΛb,where the T-odd observables are identified.We discuss the possible effects of new physics(NP)and find that the T-odd observables are sensitive to them as they vanish in the standard model.Special attention is given to the interference of(pseudo)scalar operators with(axial)vector operators in polarized Λ_(b)→Λ(→pπ^(−))τ^(+)τ^(−),which are studied for the first time.Their effects are proportional to the lepton masses and therefore may evade the constraint from Λ_(b)→Λ(→pπ^(−))μ^(+)μ^(−) at the LHCb naturally.AsΛ_(b)→Λ(→pπ^(−))τ^(+)τ^(−) is uncontaminated by the charmonia resonance,it provides a clean background to probe NP.In addition,we show that the experimental central value of K10 in Λ_(b)→Λ(→pπ^(−))μ^(+)μ^(−) at the LHCb can be explained by the NP case,which couples to the right-handed quarks and leptons.The polarization fraction of Λ_(b) at the LHCb is found to be consistent with zero regardless of the NP scenarios.展开更多
Secondary rhinoplasty to address complications from initial surgical intervention is a technically challenging operation.Common aesthetic complications that plague patients after primary rhinoplasty include nasal tip ...Secondary rhinoplasty to address complications from initial surgical intervention is a technically challenging operation.Common aesthetic complications that plague patients after primary rhinoplasty include nasal tip asymmetries,bossae,and alar retraction.These adverse outcomes are usually a result of over-manipulation and/or over-excision of native cartilage and are especially prevalent in patients with thick lower lateral cartilages and thin nasal skin.Techniques to minimize tissue handling,maintain natural nasal anatomic support and structure,and soften sharp edges from cartilage grafts or incisions are all essential in the prevention of nasal tip irregularities.In addition to prevention,there are many operative and procedural interventions to correct tip asymmetries,bossae,and alar retraction.These interventional corrections include varying cartilage and/or fascial grafts,camouflaging of previously performed grafts,and repositioning of the alar cartilage.展开更多
Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u pling.Similar emissions have been observed in all magnetic planet magnetospheres of the...Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u pling.Similar emissions have been observed in all magnetic planet magnetospheres of the solar system.In this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) hemisphere.The distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic field.In addition,the occurrence rate on the nightside clearly increases as the AE^(*) index increases.This study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.展开更多
The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productio...The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints.展开更多
The tension-compression asymmetry presents notable challenges for the application of magnesium alloys in many fields.In this study,the solid-solution treated Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy's tension-compression a...The tension-compression asymmetry presents notable challenges for the application of magnesium alloys in many fields.In this study,the solid-solution treated Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy's tension-compression asymmetry was examined using optical microscope(OM),x-ray diffraction(XRD),viscoplastic self-consistent(VPSC)modeling,and electron backscatter diffraction(EBSD).The VPSC hardening parameters were significantly adjusted based on the Schmid factor of deformation modes in rare earth magnesium(Mg-RE)alloy,which came from the EBSD data.Excellent agreement was found between the modified VPSC model's calculation results,especially the stress-strain curves and pole figures.The alloy exhibited good strength with a negligible tension-compression asymmetry and an impressive 0.98 ratio of compressive yield strength to tensile yield strength(CYS/TYS).The main cause could be attributed to the unusual texture of(11-20)<0001>in alloy,which eliminated the imbalance in tension and compression deformation by having a negative effect on the activation of{10-12}twinning in tensile and a positive effect in compressive deformation.The activation level of{10-12}twinning was 0.37 and 0.40calculated by VPSC model,in the plastic deformation of tension and compression,respectively;in the tensile and compression samples,the EBSD data indicated that approximately 31.9%and 31.1%(area proportion)of the grains were deformed with twins,respectively.Both tension and compression deformation showed the{10-12}twinning in the early stage of deformation,which transformed to{11-22}twinning in the later stage.The considerable activation of pyramidal during the later stages of deformation endowed the alloy with good ductility.展开更多
Piecewise linear systems are prevalent in engineering practice,and can be categorized into symmetric and asymmetric piecewise linear systems.Considering that symmetry is a special case of asymmetry,it is essential to ...Piecewise linear systems are prevalent in engineering practice,and can be categorized into symmetric and asymmetric piecewise linear systems.Considering that symmetry is a special case of asymmetry,it is essential to investigate the broader model,namely the asymmetric piecewise linear system.The traditional averaging method is frequently used for studying nonlinear systems,particularly symmetric piecewise linear systems,with the harmonic response of the oscillator serving as a key prerequisite for calculating steady-state solutions.However,asymmetric systems inherently exhibit nonharmonic,asymmetric responses,rendering the traditional averaging method inapplicable.To overcome this limitation,this paper introduces an improved averaging method tailored for an oscillator characterized by asymmetric gaps and springs.Unlike the traditional method,which assumes a purely harmonic response,the improved averaging method redefines the system response as a superposition of a direct current(DC)term and a first harmonic component.Herein,the DC term can be regarded as the offset induced by model asymmetry.Furthermore,the DC term is treated as a slow variable function of time,with its time derivative assumed to be zero when calculating the steady-state solution,akin to the amplitude and phase in the traditional averaging method.Numerical validation demonstrates that the responses computed in both time and frequency domains with the improved averaging method exhibit greater accuracy compared with those derived from the traditional method.Leveraging these improved results,the study also examines the parameter effect,stability,and bifurcation phenomena within the amplitude-frequency responses.展开更多
Developmental instability(DI)is a phenomenon whereby organisms are unable to buffer developmental disturbances,resulting in asymmetricvariation of paired traits.Previous research has demonstrated a negative relationsh...Developmental instability(DI)is a phenomenon whereby organisms are unable to buffer developmental disturbances,resulting in asymmetricvariation of paired traits.Previous research has demonstrated a negative relationship between DI,measured as forearm asymmetry,and survivalin the bat Carollia perspicillata.This study aims to test the hypothesis that individuals with higher DI exhibit a lower immune response.We measured a delayed-type hypersensitivity to the antigen phytohemagglutinin(PHA)on 74 males and 65 females of C.perspicillata before and after thebreeding season(BS).Linear models were used to predict the immunological response based on body mass(BM),forearm asymmetry,sex,BS,and testicle length.The best-ftting model accounted for 29% of the variation in immune response and included asymmetry,BM,sex,and BS aspredictors.The immune response was negatively associated with asymmetry and testicle length in males but positively related to asymmetryin females.Both sexes showed a reduced immune response in the late BS.Additionally,the association between immune response and BMchanged direction seasonally,with heavier individuals showing weaker responses early in the BS and stronger responses later.Individual variation in male immunity was predicted by individual attributes,whereas variation in immune response in females was mostly seasonal.Our resultssupport the link between DI,survival,and immune response in short-tailed bats,and suggest that the immunological component measured bythe PHA response may be under fner selection in males due to its stronger correlation with individual traits.展开更多
Cichlid fishes are a textbook example for adaptive radiations,since they diversified into several hundred highly specialized species in each of three great East African lakes.Even scale-eating,an extremely specialized...Cichlid fishes are a textbook example for adaptive radiations,since they diversified into several hundred highly specialized species in each of three great East African lakes.Even scale-eating,an extremely specialized feeding mode,evolved independently multiple times in these radiations and in Lake Tanganyika alone,six endemic scale-eating species occupy this extremely specialized ecological niche.Perissodus microlepis went a step further,by evolving bilaterally asymmetrical heads with an intra-specific polymorphism where left-and right-headed morphs predominantly scrape scales from the opposite sides of their prey.While the bilateral asymmetry of scale-eating cichlids has been known,exactly which craniofacial features explain the laterality of the heads remained unclear.Here we aimed,by utilizing micro-computed tomography(μCT),to resolve this issue of how bilateral symmetry in the skeletal structure is broken in scale-eating Perissodus.Our 3D geometric morphometrics analysis clearly separated and identified the two groups of either left-or right-headed fish.In addition,we observed consistent asymmetric volume changes in the premaxilla,maxilla,and mandible of the craniofacial structures,where left-headed fish have larger jaw elements on the right side,and vice versa.The bimodality implies that the effect sizes of environmental factors might be minor while genetics might be responsible to a larger extent for the asymmetry observed in their head morphology.High-speed video analyses of attacks by asymmetrical morphotypes revealed that they utilize their asymmetrical mouth protrusion,as well as lateralized behavior,to re-orientate the gape towards the preferred side of their prey fish to more efficiently scrape scales.展开更多
The grain-scale tension-compression(T-C)asymmetric slip behavior and geometrically necessary dislocation(GND)density in an aged and twin-free Mg-10Y sheet were statistically studied using slip trace analysis and elect...The grain-scale tension-compression(T-C)asymmetric slip behavior and geometrically necessary dislocation(GND)density in an aged and twin-free Mg-10Y sheet were statistically studied using slip trace analysis and electron backscatter diffraction(EBSD)analysis.A significantly asymmetric slip activity,i.e.,higher tensile slip activity and proportion of non-basal slip,was manifested.Prismatic〈a〉(37.1%)and basal〈a〉(27.6%)slips dominated the tensile deformation,followed by pyramidalⅡ〈c+a〉slip(20.0%).While during compression,basal〈a〉slip(61.9%)was the most active slip mode,and only 6.9% pyramidalⅡ〈c+a〉slip was observed.The critical resolved shear stress(CRSS)ratio was estimated based on~800 sets of the identified slip traces,which suggested that the CRSS_(pyrⅡ)/CRSS_(bas)for compression was~3 times than that of tension.The pyramidalⅡ〈c+a〉slip was more active when the slip plane was under tension than under compression,which was consistent with the calculated asymmetric CRSS_(pyrⅡ)/CRSS_(bas).The activity of multiple slip,cross slip and slip transfer,as well as the GND density were also T-C asymmetric.This work thoughtfully demonstrated the T-C asymmetric slip behavior and plastic heterogeneity in Mg alloys which was believed to be responsible for the macroscopic T-C asymmetry when twinning was absent.The present statistical results are valuable for validating and/or facilitating crystal plasticity simulations.展开更多
The anisotropy and tension-compression asymmetry of rare-earth magnesium(Mg-RE) alloys have attracted significant attention.In this study,the room-temperature tensile anisotropy and tensioncompression asymmetry of the...The anisotropy and tension-compression asymmetry of rare-earth magnesium(Mg-RE) alloys have attracted significant attention.In this study,the room-temperature tensile anisotropy and tensioncompression asymmetry of the extruded Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy were investigated utilizing techniques such as optical microscopy(OM),electron backscatter diffraction(EBSD),and viscoplastic self-consistent(VPSC) modeling.Among the tensile samples,the TO sample(with axis parallel to extrusion direction) exhibits the greatest tensile yield strength(TYS) of 270 MPa and ultimate tensile strength(UTS) of 336 MPa,the T45 sample(with axis inclined at a 45° angle to extrusion direction) and T90 sample(with axis perpendicular to extrusion direction) exhibit lower TYS and UTS.The CO sample shows a slightly greater compressive yield strength(CYS) of 290 MPa.The ratio of TYS/CYS is approximately 1.07.This study significantly adjusts the VPSC hardening parameters through the Schmid factor of deformation mechanisms in Mg-RE alloy,particularly increasing the τ0(critical resolved shear stress,CRSS) and τ1values for basalslip and {10-12} twinning.The ratios of CRSS for other deformation mechanisms to basalslip are approximately as follows:CRSSTwin/CRSSBas=2,CRSSpri/CRSSBas≈2.7and CRSSPyr/CRSSBas≈3.3,while these ratios in traditional alloys are generally higher.The stress-strain curves and pole figures obtained from the modified VPSC model demonstrate excellent agreement with experimental results.According to the VPSC simulation results,the primary factor contributing to tensile anisotropy is the disparity in the activation levels of slip systems.The inclusion of rare-earth elements mitigates the tension-compression asymmetry by reducing the difference of CRSS between different deformation mechanisms.展开更多
Pyramidal dislocations are important for ductility enhancement of magnesium alloys.In this work,molecular dynamics simulations were employed to study the gliding behavior of pyramidal(c+a)dislocations under c-axis com...Pyramidal dislocations are important for ductility enhancement of magnesium alloys.In this work,molecular dynamics simulations were employed to study the gliding behavior of pyramidal(c+a)dislocations under c-axis compressive loading and tensile loading.The Peierls stress of Py-Ⅰ dislocation shows strong tension-compression asymmetry.However,no tension-compression asymmetry is seen on the Py-Ⅱ dislocation and basal dislocation.The tension-compression asymmetry origins from the asymmetry of partial dislocations of Py-Ⅰ dislocation,which leads to the dislocation core contracted under c-axis compressive loading and expanded under tensile loading.By analyzing the forces acting on the partial dislocations,we defined a neutral direction,which deviates from the full dislocation Burgers vector by 70.3°.The neutral direction is dependent on the ratio of lattice stresses of partial dislocations.If the shear stress is applied along the neutral direction,tension-compression asymmetry is eliminated and the dislocation core is un-contracted/un-expanded.The neutral direction of symmetrical dislocations(Py-Ⅱ dislocation and basal dislocation)is just the full dislocation Burgers vector.The tension-compression asymmetry and dislocation core contraction/expansion have an important influence on the dislocation behaviors,such as cross-slip,decomposition,basaltransition and mobility,which can be used to explain the mechanical behaviors of Mg single-crystals compressed along c-axis.展开更多
基金Supported by the Medical Research Project of the Chongqing Municipal Health Commission,No.2024WSJK110.
文摘BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies.
文摘This paper seeks to highlight the macroeconomic asymmetries and social impacts among eurozone countries which occurred during the time of the financial crisis,emphasising the urgent need to revise the framework of economic governance.The analysis focuses on the growing macroeconomic and social imbalances on a representative sample of selected eurozone member-states(Euro(€)North and Euro(€)South)which had posed a threat to economic sustainability and social coherence.
基金Supported by National Natural Science Foundation of China under Grant Nos. 10721063, 10575126, and 10975169
文摘Two factorization approaches have been proposed for single transverse spin asymmetries. One is the cofiinear factorization, the other is the transverse-momentum-dependent factorization. They have been previously derived in a formal way by using diagram expansion at hadron level. If the two factorizations hold or can be proven, they should also hold when we replace hadrons with patton states. We examine these two factorizations at patton level with massless partons. It is nontrivial to generate these asymmetries at parton level with massless patrons because the asymmetries require helicity-flip and nonzero absorptive parts in scattering amplitudes. By constructing suitable patton states with massless partons we derive the two factorizations for the asymmetry in Drell-Yan processes. It is found from our results that the collinear factorization derived at parton level is not the same as that derived at hadron level. Our results with massless partons confirm those derived with single massive parton state in our previous works.
文摘Forced geostrophic turbulence on the surface of a rotating sphere (so called β-plane turbulence) is simulated trough the use of the β-SQG+1 numerical model. Domain occupied by the fluid has a channel geometry with 512 by 256 grid points, periodic boundary conditions in x-direction and rigid boundaries in y-direction. Random forcing is applied at high wave-numbers in the spectral space. To better understand eddies dynamics we simulate both regimes, with and without stochastic forcing, starting from identical initial conditions. Direct numerical simulations exhibit different dynamical properties in different regimes. In the freely evolving case, a wave term that competes with inertia on large-scales (added as a result of the β-effect) produces high meridional asymmetries in the eddies spatial and time scales. This asymmetry is added to the standard for the β-plane turbulence zonal asymmetry. In the forced regime there is not only anisotropy in the eddies deformation radius, but also in their orientation. The preferred direction for the warm anomalies elongation is north-western, while for the cold anomalies is north-eastern. These results may explain the observed meridional meandering of the mid-latitude zonal jets.
文摘An analysis of the monetary synchronization of the Union of South American Nations （UNASUR） for the decade 2004 through 2013 has been conducted using the optimum currency area （OCA） theories in order to evaluate the economic integration. By applying Bayoumi and Eichengreen＇s equation, it was found that with a decent adjustment, a high percentage of countries show a tendency to harmonize their currencies in function of the four independent variables： output disturbances, the dissimilarity in exports composition, the trade linkages, and the size of the economies. To extend the model, mobility of labor and level of the integration in good＇s market were added by modifying Behrens＇ proposal, founding that the six variables are indeed related to the exchange rate harmonization at different significant levels, with a considerable moderate fitting. Additionally an analysis of variance （ANOVA） has been considered in order to study the following economic indicators： gross domestic product （GDP）, population, GDP per capita, exports to group vs. total exports, unemployment, and inflation rates so as to visualize the economic asymmetries of the Union, for the same period. Differences were inferred for all of them but not for their annual speed of change. The least significant differences （LSD） provide further results and Duncan＇s multiple range tests lead to defining groups of countries with similar characteristics.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11345005Key Scientific Research projects of Henan Educational Committee(13A140814)the National Science Foundation under Grant No.U1332103
文摘Using the form factors calculated both in lattice QCD and HQET, we analyze the branching ratio, doublelepton polarization asymmetries and averaged double-lepton polarization asymmetries of Λ_b →Λμ^+μ^- decay in the2 HDM Ⅲ, respectively. Combining the experimental constrains on the 2HDM Ⅲ parameters, we take two set of representative parameter spaces in our calculations. For the branching ratio of Λ+b →Λμμ-decay, considering the uncertainties of the form factors and input parameters, we find the results of both SM and 2HDM Ⅲ can satisfy the current experimental data in the framework of lattice QCD, but not in HQET. Then we calculate the double-lepton polarization asymmetries Pij and their averaged values Pij, we find the double-lepton polarization asymmetries PLT,PNN, and PTT are sensitive to the 2HDM Ⅲ. However, PLN, PNL, PNT, and PTN show the opposite results. The contribution of the 2HDM Ⅲ to their averaged values have similar results.
基金supported by the National Basic Research Program of China(Grant No. 2009CB421500)the National Natural Science Foundation of China (Grant Nos. 90815028, 40405012 and 40705024)
文摘The physical processes associated with changes in the convective structure of an idealized tropical cyclone （TC） during landfall on a beta-plane were studied using the fifth-generation Pennsylvania State University- National Center for Atmospheric Research Mesoscale Model, version 3 （MM5）. The simulation results suggested that the suppression of moisture supply and increased friction acted to enhance the convection from the left and front quadrants of the TC to the front and right of the TC during different periods of landfall. When surface moisture flux was turned off, convection in other parts of the quadrant was clearly suppressed and the total rainfall was reduced. When surface friction was increased, precipitation showed a marked increase after the TC made landfall. Wetter air at low and intermediate levels, and drier air at high levels around the onshore side of the coastline led to a high value of convective available potential energy （CAPE）. Consequently, convection was enhanced immediately downstream of this area when the surface moisture flux was cut off. When surface friction was increased, the physical process was similar prior to landfall. After landfall, increased convergence at the onshore side of the land resulted in enhanced convection in front of the TC. Consistent with previous findings, our results suggest that during landfall the TC structure changes from one of thermodynamic symmetry to asymmetry due to differential moisture flux between the land and sea surface. The asymmetry of the thermodynamic structure, which can be explained by the distribution of CAPE, causes an asymmetric rainfall structure.
文摘The most powerful method to diagnose the velocity field in solar flare atmosphere isspectral analyses. That is to analyse the asymmetry and the Doppler shift of flare spectralline profiles. Recent observations indicated that at the impulsive phase of flares thereare obvious red asymmetry of Hα profiles and a downward velocity of 40-100km/s
基金Supported in part by the National Key Research and Development Program of China (2020YFC2201501)the National Natural Science Foundation of China (NSFC) (12147103)。
文摘We study the decays ofΛb→Λ(→pπ^(−))ℓ^(+)ℓ^(−)withℓ=(e,μ,τ).We examine the full angular distributions with polarizedΛb,where the T-odd observables are identified.We discuss the possible effects of new physics(NP)and find that the T-odd observables are sensitive to them as they vanish in the standard model.Special attention is given to the interference of(pseudo)scalar operators with(axial)vector operators in polarized Λ_(b)→Λ(→pπ^(−))τ^(+)τ^(−),which are studied for the first time.Their effects are proportional to the lepton masses and therefore may evade the constraint from Λ_(b)→Λ(→pπ^(−))μ^(+)μ^(−) at the LHCb naturally.AsΛ_(b)→Λ(→pπ^(−))τ^(+)τ^(−) is uncontaminated by the charmonia resonance,it provides a clean background to probe NP.In addition,we show that the experimental central value of K10 in Λ_(b)→Λ(→pπ^(−))μ^(+)μ^(−) at the LHCb can be explained by the NP case,which couples to the right-handed quarks and leptons.The polarization fraction of Λ_(b) at the LHCb is found to be consistent with zero regardless of the NP scenarios.
文摘Secondary rhinoplasty to address complications from initial surgical intervention is a technically challenging operation.Common aesthetic complications that plague patients after primary rhinoplasty include nasal tip asymmetries,bossae,and alar retraction.These adverse outcomes are usually a result of over-manipulation and/or over-excision of native cartilage and are especially prevalent in patients with thick lower lateral cartilages and thin nasal skin.Techniques to minimize tissue handling,maintain natural nasal anatomic support and structure,and soften sharp edges from cartilage grafts or incisions are all essential in the prevention of nasal tip irregularities.In addition to prevention,there are many operative and procedural interventions to correct tip asymmetries,bossae,and alar retraction.These interventional corrections include varying cartilage and/or fascial grafts,camouflaging of previously performed grafts,and repositioning of the alar cartilage.
基金supported by the National Natural Science Foundation of China grants 42230209,42374215,42304183,72342001,71931003 and 72061147004the Scientific Research Fund of Hunan Provincial Education Department grants 21A0212the Science and Technology Innovation Program of Hunan Province under Grants 2022RC4025,2023JJ50312,2023JJ50010.
文摘Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u pling.Similar emissions have been observed in all magnetic planet magnetospheres of the solar system.In this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) hemisphere.The distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic field.In addition,the occurrence rate on the nightside clearly increases as the AE^(*) index increases.This study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1611004)the National Natural Science Foundation of China(Grant Nos.12175117,12475084,and 12321005)the Shandong Province Natural Science Foundation(Grant Nos.ZFJH202303 and ZR2024MA012)。
文摘The transverse single-spin asymmetry forρ^(0) production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration.Using the Sivers function extracted from pion and kaon productions,we perform a calculation of the Sivers asymmetry within the transverse momentum-dependent factorization.Our results are consistent with the COMPASS data,supporting the universality of the Sivers function in the semi-inclusive deep inelastic scattering process for different final-state hadrons within current experimental uncertainties.While different parametrizations of the Sivers function from global analyses allow describing the data equally well,we obtain very different predictions on the Sivers asymmetry ofρand K^(*)productions at electron-ion colliders,which therefore are expected to provide further constraints.
基金financial support provided by Key Research and Development Program of Heilongjiang(Grant No.2022ZX01A01)Natural Science Found of Heilongjiang Province(LH2022E080)。
文摘The tension-compression asymmetry presents notable challenges for the application of magnesium alloys in many fields.In this study,the solid-solution treated Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy's tension-compression asymmetry was examined using optical microscope(OM),x-ray diffraction(XRD),viscoplastic self-consistent(VPSC)modeling,and electron backscatter diffraction(EBSD).The VPSC hardening parameters were significantly adjusted based on the Schmid factor of deformation modes in rare earth magnesium(Mg-RE)alloy,which came from the EBSD data.Excellent agreement was found between the modified VPSC model's calculation results,especially the stress-strain curves and pole figures.The alloy exhibited good strength with a negligible tension-compression asymmetry and an impressive 0.98 ratio of compressive yield strength to tensile yield strength(CYS/TYS).The main cause could be attributed to the unusual texture of(11-20)<0001>in alloy,which eliminated the imbalance in tension and compression deformation by having a negative effect on the activation of{10-12}twinning in tensile and a positive effect in compressive deformation.The activation level of{10-12}twinning was 0.37 and 0.40calculated by VPSC model,in the plastic deformation of tension and compression,respectively;in the tensile and compression samples,the EBSD data indicated that approximately 31.9%and 31.1%(area proportion)of the grains were deformed with twins,respectively.Both tension and compression deformation showed the{10-12}twinning in the early stage of deformation,which transformed to{11-22}twinning in the later stage.The considerable activation of pyramidal during the later stages of deformation endowed the alloy with good ductility.
基金Project supported by the National Natural Science Foundation of China(Nos.12272242 and U1934201)。
文摘Piecewise linear systems are prevalent in engineering practice,and can be categorized into symmetric and asymmetric piecewise linear systems.Considering that symmetry is a special case of asymmetry,it is essential to investigate the broader model,namely the asymmetric piecewise linear system.The traditional averaging method is frequently used for studying nonlinear systems,particularly symmetric piecewise linear systems,with the harmonic response of the oscillator serving as a key prerequisite for calculating steady-state solutions.However,asymmetric systems inherently exhibit nonharmonic,asymmetric responses,rendering the traditional averaging method inapplicable.To overcome this limitation,this paper introduces an improved averaging method tailored for an oscillator characterized by asymmetric gaps and springs.Unlike the traditional method,which assumes a purely harmonic response,the improved averaging method redefines the system response as a superposition of a direct current(DC)term and a first harmonic component.Herein,the DC term can be regarded as the offset induced by model asymmetry.Furthermore,the DC term is treated as a slow variable function of time,with its time derivative assumed to be zero when calculating the steady-state solution,akin to the amplitude and phase in the traditional averaging method.Numerical validation demonstrates that the responses computed in both time and frequency domains with the improved averaging method exhibit greater accuracy compared with those derived from the traditional method.Leveraging these improved results,the study also examines the parameter effect,stability,and bifurcation phenomena within the amplitude-frequency responses.
基金supported by Conselho Nacional de Desenvolvimento Cientifco e Tecnologico(CNPq),Fundacaode Amparoa Pesquisa do Rio de Janeiro(FAPERJ),Fundacaode Amparoa Pesquisa do Estado de Sao Paulo(FAPESPGrant nº2014/16/320-7)Coordenacao de Aperfeicoamentode Pessoal de Nível Superior(CAPES)-Finance Code 001+1 种基金by grants to LGHM and APCN from the Visiting Research Program of the FAPESP(nº2017-17607-6)supported by the PASPA-DGAPA program of the Universidad Nacional Autonoma de Mexico(nº814-2018).
文摘Developmental instability(DI)is a phenomenon whereby organisms are unable to buffer developmental disturbances,resulting in asymmetricvariation of paired traits.Previous research has demonstrated a negative relationship between DI,measured as forearm asymmetry,and survivalin the bat Carollia perspicillata.This study aims to test the hypothesis that individuals with higher DI exhibit a lower immune response.We measured a delayed-type hypersensitivity to the antigen phytohemagglutinin(PHA)on 74 males and 65 females of C.perspicillata before and after thebreeding season(BS).Linear models were used to predict the immunological response based on body mass(BM),forearm asymmetry,sex,BS,and testicle length.The best-ftting model accounted for 29% of the variation in immune response and included asymmetry,BM,sex,and BS aspredictors.The immune response was negatively associated with asymmetry and testicle length in males but positively related to asymmetryin females.Both sexes showed a reduced immune response in the late BS.Additionally,the association between immune response and BMchanged direction seasonally,with heavier individuals showing weaker responses early in the BS and stronger responses later.Individual variation in male immunity was predicted by individual attributes,whereas variation in immune response in females was mostly seasonal.Our resultssupport the link between DI,survival,and immune response in short-tailed bats,and suggest that the immunological component measured bythe PHA response may be under fner selection in males due to its stronger correlation with individual traits.
基金principally supported by Deutsche Forschungsgemeinschaft grant to A.M.a Hector Fellow Academy Ph.D.fellowship and Jim Smith Endowment Fund Grant of the Ohio Cichlid Association to X.T.Deutsche Forschungsgemeinschaft grant to J.T.
文摘Cichlid fishes are a textbook example for adaptive radiations,since they diversified into several hundred highly specialized species in each of three great East African lakes.Even scale-eating,an extremely specialized feeding mode,evolved independently multiple times in these radiations and in Lake Tanganyika alone,six endemic scale-eating species occupy this extremely specialized ecological niche.Perissodus microlepis went a step further,by evolving bilaterally asymmetrical heads with an intra-specific polymorphism where left-and right-headed morphs predominantly scrape scales from the opposite sides of their prey.While the bilateral asymmetry of scale-eating cichlids has been known,exactly which craniofacial features explain the laterality of the heads remained unclear.Here we aimed,by utilizing micro-computed tomography(μCT),to resolve this issue of how bilateral symmetry in the skeletal structure is broken in scale-eating Perissodus.Our 3D geometric morphometrics analysis clearly separated and identified the two groups of either left-or right-headed fish.In addition,we observed consistent asymmetric volume changes in the premaxilla,maxilla,and mandible of the craniofacial structures,where left-headed fish have larger jaw elements on the right side,and vice versa.The bimodality implies that the effect sizes of environmental factors might be minor while genetics might be responsible to a larger extent for the asymmetry observed in their head morphology.High-speed video analyses of attacks by asymmetrical morphotypes revealed that they utilize their asymmetrical mouth protrusion,as well as lateralized behavior,to re-orientate the gape towards the preferred side of their prey fish to more efficiently scrape scales.
基金supported by the National Natural Science Foundation of China(No.52171125)the Sichuan Science and Technology Program(No.2024NSFSC0193)。
文摘The grain-scale tension-compression(T-C)asymmetric slip behavior and geometrically necessary dislocation(GND)density in an aged and twin-free Mg-10Y sheet were statistically studied using slip trace analysis and electron backscatter diffraction(EBSD)analysis.A significantly asymmetric slip activity,i.e.,higher tensile slip activity and proportion of non-basal slip,was manifested.Prismatic〈a〉(37.1%)and basal〈a〉(27.6%)slips dominated the tensile deformation,followed by pyramidalⅡ〈c+a〉slip(20.0%).While during compression,basal〈a〉slip(61.9%)was the most active slip mode,and only 6.9% pyramidalⅡ〈c+a〉slip was observed.The critical resolved shear stress(CRSS)ratio was estimated based on~800 sets of the identified slip traces,which suggested that the CRSS_(pyrⅡ)/CRSS_(bas)for compression was~3 times than that of tension.The pyramidalⅡ〈c+a〉slip was more active when the slip plane was under tension than under compression,which was consistent with the calculated asymmetric CRSS_(pyrⅡ)/CRSS_(bas).The activity of multiple slip,cross slip and slip transfer,as well as the GND density were also T-C asymmetric.This work thoughtfully demonstrated the T-C asymmetric slip behavior and plastic heterogeneity in Mg alloys which was believed to be responsible for the macroscopic T-C asymmetry when twinning was absent.The present statistical results are valuable for validating and/or facilitating crystal plasticity simulations.
基金Project supported by the Key Research and Development Program of Heilongjiang (2022ZX01A01)National Natural Science Foundation of China (51975167)Natural Science Foundation of Heilongjiang Province(LH2022E080)
文摘The anisotropy and tension-compression asymmetry of rare-earth magnesium(Mg-RE) alloys have attracted significant attention.In this study,the room-temperature tensile anisotropy and tensioncompression asymmetry of the extruded Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy were investigated utilizing techniques such as optical microscopy(OM),electron backscatter diffraction(EBSD),and viscoplastic self-consistent(VPSC) modeling.Among the tensile samples,the TO sample(with axis parallel to extrusion direction) exhibits the greatest tensile yield strength(TYS) of 270 MPa and ultimate tensile strength(UTS) of 336 MPa,the T45 sample(with axis inclined at a 45° angle to extrusion direction) and T90 sample(with axis perpendicular to extrusion direction) exhibit lower TYS and UTS.The CO sample shows a slightly greater compressive yield strength(CYS) of 290 MPa.The ratio of TYS/CYS is approximately 1.07.This study significantly adjusts the VPSC hardening parameters through the Schmid factor of deformation mechanisms in Mg-RE alloy,particularly increasing the τ0(critical resolved shear stress,CRSS) and τ1values for basalslip and {10-12} twinning.The ratios of CRSS for other deformation mechanisms to basalslip are approximately as follows:CRSSTwin/CRSSBas=2,CRSSpri/CRSSBas≈2.7and CRSSPyr/CRSSBas≈3.3,while these ratios in traditional alloys are generally higher.The stress-strain curves and pole figures obtained from the modified VPSC model demonstrate excellent agreement with experimental results.According to the VPSC simulation results,the primary factor contributing to tensile anisotropy is the disparity in the activation levels of slip systems.The inclusion of rare-earth elements mitigates the tension-compression asymmetry by reducing the difference of CRSS between different deformation mechanisms.
基金financially supported by National Natural Science Foundation of China(12072211,12232008)Foundation of Key laboratory(2022JCJQLB05703)Sichuan Province Science and Technology Project(2023NSFSC0914)。
文摘Pyramidal dislocations are important for ductility enhancement of magnesium alloys.In this work,molecular dynamics simulations were employed to study the gliding behavior of pyramidal(c+a)dislocations under c-axis compressive loading and tensile loading.The Peierls stress of Py-Ⅰ dislocation shows strong tension-compression asymmetry.However,no tension-compression asymmetry is seen on the Py-Ⅱ dislocation and basal dislocation.The tension-compression asymmetry origins from the asymmetry of partial dislocations of Py-Ⅰ dislocation,which leads to the dislocation core contracted under c-axis compressive loading and expanded under tensile loading.By analyzing the forces acting on the partial dislocations,we defined a neutral direction,which deviates from the full dislocation Burgers vector by 70.3°.The neutral direction is dependent on the ratio of lattice stresses of partial dislocations.If the shear stress is applied along the neutral direction,tension-compression asymmetry is eliminated and the dislocation core is un-contracted/un-expanded.The neutral direction of symmetrical dislocations(Py-Ⅱ dislocation and basal dislocation)is just the full dislocation Burgers vector.The tension-compression asymmetry and dislocation core contraction/expansion have an important influence on the dislocation behaviors,such as cross-slip,decomposition,basaltransition and mobility,which can be used to explain the mechanical behaviors of Mg single-crystals compressed along c-axis.
