1,415 research outputs found

    The potential for reassortment between Oropouche and Schmallenberg Orthobunyaviruses

    Get PDF
    A number of viruses within the Peribunyaviridae family are naturally occurring reassortants, a common phenomenon for segmented viruses. Using a minigenome-reporter and virus-like particle (VLP) production assay, we have accessed the potential of Oropouche virus (OROV), Schmallenberg virus (SBV), and other orthobunyaviruses within the Simbu serogroup to reassort. We found that the untranslated region (UTR) in the medium segment is a potential contributing factor for reassortment by the tested viruses. We demonstrate that for promoter activity to occur it was essential that the viral RNA polymerase (L) and nucleocapsid (N) proteins were from the same virus, reinforcing the hypothesis that the large and small segments that encode these proteins segregate together during genome reassortment. Our results indicate that, given the right epidemiological setting, reassortment between SBV and OROV would potentially be feasible and could contribute to the emergence of a new Simbu virus

    Impact of the Desert dust on the summer monsoon system over Southwestern North America

    Get PDF
    The radiative forcing of dust emitted from the Southwest United States (US) deserts and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for 15 years (1995–2009). During the monsoon season, dust has a cooling effect (−0.90 W m<sup>−2</sup>) at the surface, a warming effect (0.40 W m<sup>−2</sup>) in the atmosphere, and a negative top-of-the-atmosphere (TOA) forcing (−0.50 W m<sup>−2</sup>) over the deserts on 24-h average. Most of the dust emitted from the deserts concentrates below 800 hPa and accumulates over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day<sup>−1</sup> over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August) show that dust heating of the lower atmosphere over the deserts strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to ~40 % over the eastern slope of the Mountains (Arizona-New~Mexico-Texas regions). This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the mega-drought conditions projected for the future

    Radiative impact of mineral dust on monsoon precipitation variability over West Africa

    Get PDF
    The radiative forcing of dust and its impact on precipitation over the West Africa monsoon (WAM) region is simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem). During the monsoon season, dust is a dominant contributor to aerosol optical depth (AOD) over West Africa. In the control simulation, on 24-h domain average, dust has a cooling effect (−6.11 W m<sup>−2</sup>) at the surface, a warming effect (6.94 W m<sup>−2</sup>) in the atmosphere, and a relatively small TOA forcing (0.83 W m<sup>−2</sup>). Dust modifies the surface energy budget and atmospheric diabatic heating. As a result, atmospheric stability is increased in the daytime and reduced in the nighttime, leading to a reduction of late afternoon precipitation by up to 0.14 mm/h (25%) and an increase of nocturnal and early morning precipitation by up to 0.04 mm/h (45%) over the WAM region. Dust-induced reduction of diurnal precipitation variation improves the simulated diurnal cycle of precipitation when compared to measurements. However, daily precipitation is only changed by a relatively small amount (−0.17 mm/day or −4%). The dust-induced change of WAM precipitation is not sensitive to interannual monsoon variability. On the other hand, sensitivity simulations with weaker to stronger absorbing dust (in order to represent the uncertainty in dust solar absorptivity) show that, at the lower atmosphere, dust longwave warming effect in the nighttime surpasses its shortwave cooling effect in the daytime; this leads to a less stable atmosphere associated with more convective precipitation in the nighttime. As a result, the dust-induced change of daily WAM precipitation varies from a significant reduction of −0.52 mm/day (−12%, weaker absorbing dust) to a small increase of 0.03 mm/day (1%, stronger absorbing dust). This variation originates from the competition between dust impact on daytime and nighttime precipitation, which depends on dust shortwave absorption. Dust reduces the diurnal variation of precipitation regardless of its absorptivity, but more reduction is associated with stronger absorbing dust

    Topological carbon materials: a new perspective

    Full text link
    Carbon has numerous one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) allotropic structures. The study of carbon materials has been a major focus of material science and condensed matter physics. Previous studies have identified different classes of topological semimetallic carbon allotropes with different topological phases. In this review, we first give a brief summary of the development of carbon allotropes from 1D to 3D. Next, we discuss topological properties of carbon materials and their physical origin. Then, we consider possible expansion of the topological study of carbon materials to other light-element materials such as boron. Finally, we present future prospects in pursue of topological physics within carbon allotropes

    Regulatory T Cells Are Dispensable for Tolerance to RBC Antigens

    Get PDF
    Autoimmune hemolytic anemia (AIHA) occurs when pathogenic autoantibodies against red blood cell (RBC) antigens are generated. Whilst the basic disease pathology of AIHA is well studied, the underlying mechanism(s) behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs) in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved

    The specific capacitance of sol–gel synthesised spinel MnCo2O4 in an alkaline electrolyte

    Get PDF
    PublishedArticleIn this work, high performance spinel MnCo2O4 electrode was fabricated via a facile sol–gel method and its capacitive behavior was successfully investigated in alkaline electrolyte. MnCo2O4 electrode was characterized by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The pseudo capacitive behavior of spinel MnCo2O4 was widely investigated in 2 M KOH aqueous electrolyte using cyclic voltammetry (CV), galvanostatic charge-discharge test, and electrochemical impedance spectroscopy (EIS). As a result, the spinel MnCo2O4 exhibited excellent porous structure and the highest specific capacitance of 405 F g−1 was achieved at a current density of 5 mA cm−2. In addition, the spinel MnCo2O4 displayed desirable stability in alkaline electrolyte during long-term cycles with a cycling efficiency of 95.1% over 1,000 cycles. The high specific capacitance and excellent cycling ability of MnCo2O4 show promise for its application in supercapacitors.National Natural Science Foundation of ChinaChinese Ministry of EducationNatural Science Funds for Distinguished Young Scholars of Gansu ProvinceProgram for Hongliu Outstanding Talents in Lanzhou University of Technolog

    A sol-gel process for the synthesis of NiCo2O4 having improved specific capacitance and cycle stability for electrochemical capacitors

    Get PDF
    PublishedArticleHigh performance nickel cobaltite (NiCo2O4) with ultrahigh capacitance is synthesized by a facile sol-gel process and then calcined at 300◦C. The structure and morphology is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and nitrogen adsorption/desorption experiments.Amesoporous structure with high specific surface area is obtained. Electrochemical properties are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS). The NiCo2O4 exhibits excellent electrochemical performance. The highest specific capacitance of 1128 F g−1 is achieved at a current density of 5 mA cm−2 and 92.5% of the initial specific capacitance remained after 1000 cycles. NiCo2O4 prepared by this scale-able route could be a promising electrode material for electrochemical capacitors.National Natural Science Foundation of ChinaKey Project of Chinese Ministry of EducationNatural Science Funds for Distinguished Young Scholars of Gansu Provinc

    Effects of Unconscious Processing on Implicit Memory for Fearful Faces

    Get PDF
    Emotional stimuli can be processed even when participants perceive them without conscious awareness, but the extent to which unconsciously processed emotional stimuli influence implicit memory after short and long delays is not fully understood. We addressed this issue by measuring a subliminal affective priming effect in Experiment 1 and a long-term priming effect in Experiment 2. In Experiment 1, a flashed fearful or neutral face masked by a scrambled face was presented three times, then a target face (either fearful or neutral) was presented and participants were asked to make a fearful/neutral judgment. We found that, relative to a neutral prime face (neutral–fear face), a fearful prime face speeded up participants' reaction to a fearful target (fear–fear face), when they were not aware of the masked prime face. But this response pattern did not apply to the neutral target. In Experiment 2, participants were first presented with a masked faces six times during encoding. Three minutes later, they were asked to make a fearful/neutral judgment for the same face with congruent expression, the same face with incongruent expression or a new face. Participants showed a significant priming effect for the fearful faces but not for the neutral faces, regardless of their awareness of the masked faces during encoding. These results provided evidence that unconsciously processed stimuli could enhance emotional memory after both short and long delays. It indicates that emotion can enhance memory processing whether the stimuli are encoded consciously or unconsciously
    • …
    corecore