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Cortical fast-spiking (FS) neurons generate high-frequency action potentials (APs) without apparent frequency accommodation, thus providing fast and precise inhibition. However, the maximal firing frequency that they can reach, particularly in primate neocortex, remains unclear. Here, by recording in human, monkey, and mouse neocortical slices, we revealed that FS neurons in human association cortices (mostly temporal) could generate APs at a maximal mean frequency (Fmean) of 338 Hz and a maximal instantaneous frequency (Finst) of 453 Hz, and they increase with age. The maximal firing frequency of FS neurons in the association cortices (frontal and temporal) of monkey was even higher (Fmean 450 Hz, Finst 611 Hz), whereas in the association cortex (entorhinal) of mouse it was much lower (Fmean 215 Hz, Finst 342 Hz). Moreover, FS neurons in mouse primary visual cortex (V1) could fire at higher frequencies (Fmean 415 Hz, Finst 582 Hz) than those in association cortex. We further validated our in vitro data by examining spikes of putative FS neurons in behaving monkey and mouse. Together, our results demonstrate that the maximal firing frequency of FS neurons varies between species and cortical areas. [ABSTRACT FROM AUTHOR]

Two incongruent images viewed by the two eyes cause binocular rivalry, during which observers perceive continuous alternations between these two visual images. Previous studies in both humans and monkeys have shown that the primary visual cortex (V1) plays a critical role in the rivalry perception. However, it is unclear whether the rivalry activity observed in VI relies on conscious influences. Here, we examine the responses of VI in monkeys under general anesthesia. With intrinsic signal optical imaging and single-trial analysis, alternating activation of ocular dominance columns in V1 was observed during binocularly incongruent stimulation. Left- and right-eye columns exhibited counterphase activation, which were modulated by stimulus features in ways similar to those found in conscious human observers. These observations indicated that binocular rivalry occurs in V1 without consciousness, suggesting that the low-level automatic mechanisms play a more important role than previously believed in handling visual ambiguities [ABSTRACT FROM AUTHOR]

Visual processing depends critically on the receptive field (RF) properties of visual neurons. However, comprehensive characterization of RFs beyond the primary visual cortex (V1) remains a challenge. Here we report fine RF structures in secondary visual cortex (V2) of awake macaque monkeys, identified through a projection pursuit regression analysis of neuronal responses to natural images. We found that V2 RFs could be broadly classified as V1-like (typical Gaborshaped subunits), ultralong (subunits with high aspect ratios), or complex-shaped (subunits with multiple oriented components). Furthermore, single-unit recordings from functional domains identified by intrinsic optical imaging showed that neurons with ultralong RFs were primarily localized within pale stripes, whereas neurons with complex-shaped RFs were more concentrated in thin stripes. Thus, by combining single-unit recording with optical imaging and a computational approach, we identified RF subunits underlying spatial feature selectivity of V2 neurons and demonstrated the functional organization of these RF properties. [ABSTRACT FROM AUTHOR]

Electrically driven reversible structural conversion between the MAPbI3 and PbI2 phase in MAPbI3 at 330 K is first reported, which provides insights into the intrinsic stability and chemical activities of MAPbI3 materials. Meanwhile, direct visualization of the macro­scopic migration of iodine anions is also reported for the first time, which provides strong evidence for the iodine ions migration. [ABSTRACT FROM AUTHOR]

In first-line antiretroviral therapy (ART) for human immunodeficiency virus (HIV) treatment, some subgroups of patients may respond better to an efavirenz-based regimen than an integrase strand transfer inhibitor (InSTI)-based regimen, or vice versa, due to patient characteristics modifying treatment effects. Using data based on nearly 16,000 patients from the North American AIDS Cohort Collaboration on Research and Design from 2009–2016, statistical methods for precision medicine were employed to estimate an optimal treatment rule that minimizes the 5-year risk of the composite outcome of acquired immune deficiency syndrome (AIDS)-defining illnesses, serious non-AIDS events, and all-cause mortality. The treatment rules considered were functions that recommend either an efavirenz- or InSTI-based regimen conditional on baseline patient characteristics such as demographic information, laboratory results, and health history. The estimated 5-year risk under the estimated optimal treatment rule was 10.0% (95% confidence interval (CI): 8.6, 11.3), corresponding to an absolute risk reduction of 2.3% (95% CI: 0.9, 3.8) when compared with recommending an efavirenz-based regimen for all patients and 2.6% (95% CI: 1.0, 4.2) when compared with recommending an InSTI-based regimen for all. Tailoring ART to individual patient characteristics may reduce 5-year risk of the composite outcome compared with assigning all patients the same drug regimen. [ABSTRACT FROM AUTHOR]

In the present maize production in China, the problem of agricultural machinery and agronomic technology not supporting the link of maize planting, soil tillage and maize planting has been significantly restricting the increase of maize yield levels and production capability. In order to resolve the problem that the good agronomic practices and agricultural machinery are not currently combined, a new maize planter based on wide-narrow row strip deep rotation and no-tillage technology was used in Weibei dry land in 2011 and 2012. Measured quantities were soil quality, soil moisture, maize emergence rate, field light distribution of maize groups, corn root growth number, and yield traits after this mechanical and ordinary seeder operations in spring corn field. The results show that through adopting the cultivation principle that combined strip-rotating in 40 cm narrow row with no-tillage in 80 cm wide row and integration of excellent seeding technique, deep application of fertilizer, deep rotation technology, no-tillage technology, and wide-narrow row planting technology, the machine can improve soil physical properties and maize population characteristics during the growth period. With the planter seeding, it can effectively break the plough pan and reduce soil bulk density in the 0-30 cm soil layer in narrow deep rotation rows, increasing the mass of maize root, increasing the soil water storage capacity, and significantly enhancing the quality of corn planting groups and population light transmittance. The yield of spring maize and water use efficiency significantly increased after using the planter. The soil bulk density of deep rotation row with precise mechanical sowing of maize based on wide-narrow row strip deep rotation and no-tillage technology is reduced, soil water storage in deep loosening row noticeably improved in later growth stage, soil water content of no-tillage trip with significantly raised in earlier growth stage, the seedling germination rate of maize increased 6.2 percentage points, and the plant height variation coefficient within the field at jointing period decreased 8.33% than those with the ordinary planter. As the same time, root dry weight of maize at the jointing period increased 15.79%, the light intercepted by the population of maize at the later spinning stage significantly increased 22.47%-23.45%, 1000-grain weight increased an average of 3.73%, the effective panicle number per hectare increased an average of 5.84%, and yield increased an average of 11.15% compared with ordinary machine sowing. The combination of good agronomic measures and agricultural machinery is realized in this system, and it can further promote maize grain production and farmers' income in this region. [ABSTRACT FROM AUTHOR]

Historically, vision research in China was one of a few distinct research programs within the Chinese Academy of Sciences (CAS). With improved funding opportunities and research environment in neuroscience, vision research at several research institutes within the academy has made significant progress not only in the quantity of publications, but also in the quality of the work. Based on our own expertise, this review is mainly focused on the findings that have advanced the understanding of visual processing in the central visual pathway, visual perceptual learning, visual development and eye diseases. [ABSTRACT FROM AUTHOR]

A correction for the article "Clinical Effectiveness of Integrase Strand Transfer Inhibitor–Based Antiretroviral Regimens Among Adults With Human Immunodeficiency Virus: A Collaboration of Cohort Studies" is presented, which is published in the September 2020 issue of the periodical.

ABSTRACT: A Volume of Fluid (VOF) technique has been further developed and coupled with an incompressible Euler/Navier Stokes solver operating on adaptive, unstructured grids to simulate the interactions of extreme waves and a LNG carrier with full or partially filled tanks. The present implementation follows the classic VOF implementation for the liquid-gas system, considering only the liquid phase. Extrapolation algorithms are used to obtain velocities and pressures in the gas region near the free surface. An arbitrary Lagrangian-Eulerian (ALE) frame of reference is used. The mesh is moved in such a way as to minimize the distortion of the mesh due to body movement. The incompressible Euler/Navier-Stokes equations are solved using projection schemes and a finite element method on unstructured grids, and the free surface is captured by the VOF method. The computer code developed based on the method described above is used in this study to simulate a numerical seakeeping tank, where the waves are generated by the sinusoidal excitation of a piston paddle, and a freely-floating LNG carrier with full or partially filled tanks moves in response to the waves. Both head sea and oblique sea are considered in the simulation. Highly nonlinear wave-body interactions, such as green water on deck and sloshing, have been modeled successfully. [Copyright &y& Elsevier]

In the context of global warming, the effects of warming in the root zone of crops on maize seedling characteristics deserve research attention. Previous studies on the adaptive traits of dryland maize have mainly focused on soil moisture and nutrients, rather than analyzing potential factors for the adaptive traits of root zone warming. This study was conducted to investigate the effects of different root zone warming ranges on the agronomic traits, hormones, and microstructures of maize seedling roots and leaves. The results showed that minor increases in the root zone temperature significantly enhanced maize seedling growth. However, when the temperature in the root zone was excessive, the stem diameter, root surface area, root volume, total root length, dry matter accumulation, and root/shoot biomass of maize seedlings sharply decreased. Under high temperature stress in the root zone, the root conduit area; root stele diameter; root content of trans-zeatin (ZT), gibberellin A3 (GA3), and indoleacetic acid (IAA); leaf thickness; upper and lower epidermis thickness; and leaf content of ZT and GA3 were significantly decreased. The hormone content and microstructure changes might be an important reason for root growth maldevelopment and nutrient absorption blockage, and they also affected the leaf growth of maize seedlings. Compared with the 'senescent' maize type Shaandan 902 (SD902), the plant microstructure of the 'stay-green' maize type Shaandan 609 (SD609) was less affected by increased temperatures, and the ability of the root system to absorb and transport water was stronger, which might explain its tolerance of high temperature stress in the root zone. [ABSTRACT FROM AUTHOR]

In mammals, a larger number of neurons in V1 are devoted to cardinal (horizontal and vertical) orientations than to oblique orientations. However, electrophysiological results from the macaque monkey visual cortex are controversial. Both isotropic and anisotropic orientation distributions have been reported. It is also unclear whether different visual areas along the visual hierarchy have different orientation anisotropies. We analyzed orientation maps in a large set of intrinsic signal optical imaging data and found that both V1 and V4 exhibited significant orientation anisotropies. However, their overrepresented orientations were very different: in V1, both cardinal and radial orientations were overrepresented, while in V4, only cardinal bias was presented. These findings suggest that different cortical areas have evolved to emphasize different features that are suitable for their functional purposes, a factor that needs to be considered when efforts are made to explain the relationships between the visual environment and the cortical representation and between the cortical representation and visual perception. [ABSTRACT FROM AUTHOR]

Background: HIV self-testing (HIVST) is a promising approach to expand HIV testing. HIVST is a process in which a person performs an HIV test and interprets the result. Negative HIVST results may encourage men who have sex with men (MSM) to use HIV prevention services. The objective of this study was to examine behaviors (e.g., facility-based HIV testing, condom use) after a negative HIVST test result among Chinese MSM.Methods: We collected data from MSM in eight Chinese cities over a 12-month period. This is a secondary analysis of longitudinal cohort data collected as part of an intervention trial to increase HIV testing. Men completed a survey that described sociodemographic information, sexual behaviors, HIV self-testing, and facility-based HIV testing. Men who completed at least one follow-up survey were included in this analysis. Generalized linear mixed models were used to evaluate whether HIVST increased subsequent facility-based HIV testing and consistent condom use.Results: We included 1219 men. Most men (78.7%) were under 30 years old and had never been married (87.0%). 755 (61.9%) men tested for HIV and 593 (49.3%) men self-tested during the study period. At baseline, among men who had never been tested for HIV, 44.9% (314/699) initiated HIVST during the study period. HIVST was associated with subsequent facility-based testing (aOR of 1.87, 95% CI: 1.47-2.37). HIVST was also associated with subsequent consistent condom use (aOR = 1.53, 95% CI: 1.13-2.06).Conclusion: HIVST was associated with subsequent facility-based HIV testing and consistent condom use. HIVST may enhance uptake of related HIV prevention services at facilities, suggesting the need for more implementation research. [ABSTRACT FROM AUTHOR]

Background: The spread of healthy behaviors through social networks may be accelerated by influential individuals. Previous studies have used lay health influencers to prevent sexually transmitted infections (STIs) among internet-using men who have sex with men (MSM). However, there is a lack of understanding of the characteristics of this key subset of MSM.Objective: This study aimed to examine sociodemographic characteristics, HIV and syphilis testing, and sexual behaviors of Web-based MSM sexual health influencers (SHIs) in China, defined as individuals with relatively stronger influence on spreading HIV and STI information online.Methods: A Web-based survey of MSM was conducted in August 2017 as a final follow-up of a randomized controlled trial promoting HIV testing in 8 Chinese cities. Men were recruited through a gay social networking mobile phone app and were included if they were born biologically male, aged 16 years and above, ever had sex with another man, and HIV negative or with unknown HIV status. Information regarding sociodemographic characteristics, sexual behaviors, and HIV and syphilis testing was obtained. We assessed men's Web-based sexual health influence using a standardized 6-item opinion leadership scale focused on HIV and STI information. Influencers were defined as those whose mean score ranked within the top 13% (a higher score means greater influence). We used multivariable linear and logistic regression models to measure Web-based sexual health influence's association with HIV and syphilis testing, controlling for intervention trial effects, age, education, income, and marital status.Results: Overall, 1031 men completed the survey. Most men were younger than 30 years (819/1031, 79.43%) and had at least college education (667/1031, 64.69%). Influencers were more likely to get tested for HIV (73/132, 55.3% vs 337/899, 37.5%; P<.001) and syphilis (35/132, 26.5% vs 137/899, 15.2%; P=.001) in the last 3 months compared with noninfluencers. There were no significant differences in condomless sex with male partners (26/132, 19.7% vs 203/899, 22.6%; P=.46), mean number of male sex partners (1.32 vs 1.11; P=.16) in the last 3 months, and mainly meeting male sex partners online in the last 12 months (97/132, 73.5% vs 669/899, 74.4%; P=.82) between influencers and noninfluencers. Regression analyses showed that influencers had higher odds of HIV testing (adjusted odds ratio, AOR 2.16, 95% CI 1.48-3.17) and syphilis testing (AOR 1.99, 95% CI 1.28-3.10) in the last 3 months.Conclusions: We identified Web-based SHIs who might be more likely to help promote healthy HIV and syphilis testing behaviors through MSM populations. Leveraging existing influencers may help improve HIV and syphilis testing among their networks. [ABSTRACT FROM AUTHOR]

Domain orientations and their volume ratios in ferroelectrics are recognized as a compelling topic recently for domain switching dynamics and domain stability in devices application. Here, an optimized second harmonic generation method has been explored for ferroelectric domain characterization. Combing a unique theoretical model with azimuth-polarization-dependent second harmonic generation response, the complex domain components and their distributions can be rigidly determined in ferroelectric thin films. Using the proposed model, the domain structures of rhombohedral BiFeO3 films with 71° and 109° domain wall, and, tetragonal BiFeO3, Pb(Zr0.2Ti0.8)O3, and BaTiO3 ferroelectric thin films are analyzed and the corresponding polarization variants are determined. This work could provide a powerful and all-optical method to track and evaluate the evolution of ferroelectric domains in the ferroelectric-based devices. Ferroelectrics: optical method characterizes domain structures An optimized optical method is developed to determine the ferroelectric domain structure and their distributions in several ferroelectric films. A team led by Xiangli Zhong and Yichun Zhou from Xiangtan University, and Jianmin Yuan from National University of Defense Technology in China, combined optimized second harmonic generation (SHG) measurements and theoretical analysis to determine the polarization components of domains and their distribution in rhobohedral BiFeO3, tetragonal BiFeO3, Pb(Zr0.2Ti0.8)O3 and BaTiO3 thin films. They first collect azimuth-polarization-dependent SHG signals with respect to both the polarization angle of the incident beam and the azimuth angle of sample relative to the beam. Then they fit the SHG signals with a theoretical model with good agreement. This work provides an effective and all-optical method to determine the domain structures and distributions for ferroelectric thin films. [ABSTRACT FROM AUTHOR]

In the ferroelectric devices, polarization control is usually accomplished by application of an electric field. In this paper, we demonstrate optically induced polarization switching in BaTiO3-based ferroelectric heterostructures utilizing a two-dimensional narrow-gap semiconductor MoS2 as a top electrode. This effect is attributed to the redistribution of the photo-generated carriers and screening charges at the MoS2/BaTiO3 interface. Specifically, a two-step process, which involves formation of intra-layer excitons during light absorption followed by their decay into inter-layer excitons, results in the positive charge accumulation at the interface forcing the polarization reversal from the upward to the downward direction. Theoretical modeling of the MoS2 optical absorption spectra with and without the applied electric field provides quantitative support for the proposed mechanism. It is suggested that the discovered effect is of general nature and should be observable in any heterostructure comprising a ferroelectric and a narrow gap semiconductor. Controlling the polarization state in ferroeletric materials is a prerequisite for their application. Here an approach is presented to optically manipulate the polarization of ferroelectric BaTiO3 by exploiting photogenerated carriers at the interface with a two-dimensional semiconducting MoS2 film. [ABSTRACT FROM AUTHOR]