Precipitation variation: a key factor regulating plant diversity in semi-arid livestock grazing lands.

Livestock presence impacts plant biodiversity (species richness) in grassland ecosystems, yet extent and direction of grazing impacts on biodiversity vary greatly across inter-annual periods. In this study, an 8-year (2014-2021) grazing gradient experiment with sheep was conducted in a semi-arid grassland to investigate the impact of grazing under different precipitation variability on biodiversity. The results suggest no direct impact of grazing on species richness in semi-arid Stipa grassland. However, increased grazing indirectly enhanced species richness by elevating community dominance (increasing the sheltering effect of Stipa grass). Importantly, intensified grazing also regulates excessive community biomass resulting from increased inter-annual wetness (SPEI), amplifying the positive influence of annual humidity index on species richness. Lastly, we emphasize that, in water-constrained grassland ecosystems, intra-annual precipitation variability (PCI) was the most crucial factor driving species richness. Therefore, the water-heat synchrony during the growing season may alleviate physiological constraints on plants, significantly enhancing species richness as a result of multifactorial interactions. Our study provides strong evidence for how to regulate grazing intensity to increase biodiversity under future variable climate patterns. We suggest adapting grazing intensity according to local climate variability to achieve grassland biodiversity conservation.

[Current status of animal experiment report of acupuncture intervention in chronic fatigue syndrome based on ARRIVE guidelines and GSPC list].

OBJECTIVE: To analyze the current status of animal experiments of acupuncture in intervening chronic fatigue syndrome, so as to search formethods to improve the quality of animal experiment reports. METHODS: From the databases, such as CNKI, VIP, Wanfang, SinoMed, PubMed, Web of Science, Embase and Cochrane Library, the literature of animal experiment on acupuncture treatment for chronic fatigue syndrome was searched from January 1st, 2011 to April 2nd, 2022. Data were extracted according to the animal research reporting in vivo experiment (ARRIVE) guidelines 2.0 and gold standard publication checklist (GSPC), and statistical analysis was performed using Excel 2019. RESULTS: A total of 16 studies were finally included. The satis-faction rate of essential items in the ARRIVE guidelines 2.0 is 41.76%，while the satisfaction rate of recommended items is only 27.73% and of the GSPC is 25.89%. Out of 16 studies, 13 of them explained the reasons for animal exclusion in the experiment, 8 provided specific randomized methods, 8 described detailed information on animal species, strains, and quantities, 3 basically indicated that they had passed ethical review, 7 explained the limitations of the research. All 16 studies reported the main findings and elucidated their potential clinical or scientific value. CONCLUSION: Current animal studies on acupuncture in intervening the chronic fatigue syndrome are of certain limitation. Descriptions of multiple items are incomplete or missing, which prevents rea-ders from assessing reliability and authenticity of the animal experiment. It is recommended that in future research, experimental design, execution and report should be carried out according to the report guidelines for animal experiment to improve research quality.

Light People: Professor Martin Booth spoke about adaptive optics and its applications.

EDITORIAL: Adaptive optics (AO), a technique originally introduced by astronomers to correct for optical distortions when looking at distant stars, now benefits the entire optics and photonics society. Prof. Martin Booth, who leads his research lab at the University of Oxford where he started his career, was one of the first people to take advantage of AO for microscopy. Since then, he has been continuously promoting the wide application of AO in all aspects of biological research and material science. As one of the few people who has witnessed the growth of AO in various communities, Prof. Martin Booth talks about their major differences, as well as their current challenges and future development. He discusses how AO can benefit emerging areas and the key challenges that may be faced. Prof. Martin Booth has also been making continuous efforts in removing the barriers of AO so that it can be promoted towards the wider community. Finally, he shares his experience from actively taking up different roles in education and in various societies and provides valuable advice to all early career researchers on the wisdom of being successful in their future careers. It is an honour for us to invite Prof. Martin Booth on this issue, and to learn from his inspirations, enthusiasm, and dedication.

Generalised adaptive optics method for high-NA aberration-free refocusing in refractive-index-mismatched media.

Phase aberrations are introduced when focusing by a high-numerical aperture (NA) objective lens into refractive-index-mismatched (RIM) media. The axial focus position in these media can be adjusted through either optical remote-focusing or mechanical stage translation. Despite the wide interest in remote-focusing, no generalised control algorithm using Zernike polynomials has been presented that performs independent remote-focusing and RIM correction in combination with mechanical stage translation. In this work, we thoroughly review derivations that model high-NA defocus and RIM aberration. We show through both numerical simulation and experimental results that optical remote-focusing using an adaptive device and mechanical stage translation are not optically equivalent processes, such that one cannot fully compensate for the other without additional aberration compensation. We further establish new orthogonal modes formulated using conventional Zernike modes and discuss its device programming to control high-NA remote-focusing and RIM correction as independent primary modes in combination with mechanical stage translation for aberration-free refocusing. Numerical simulations are performed, and control algorithms are validated experimentally by fabricating graphitic features in diamond using direct laser writing.

Extended range and aberration-free autofocusing via remote focusing and sequence-dependent learning.

Rapid autofocusing over long distances is critical for tracking 3D topological variations and sample motion in real time. Taking advantage of a deformable mirror and Shack-Hartmann wavefront sensor, remote focusing can permit fast axial scanning with simultaneous correction of system-induced aberrations. Here, we report an autofocusing technique that combines remote focusing with sequence-dependent learning via a bidirectional long short term memory network. A 120 µm autofocusing range was achieved in a compact reflectance confocal microscope both in air and in refractive-index-mismatched media, with similar performance under arbitrary-thickness liquid layers up to 1 mm. The technique was validated on sample types not used for network training, as well as for tracking of continuous axial motion. These results demonstrate that the proposed technique is suitable for real-time aberration-free autofocusing over a large axial range, and provides unique advantages for biomedical, holographic and other related applications.

Compact and contactless reflectance confocal microscope for neurosurgery.

Visual guidance at the cellular level during neurosurgical procedures is essential for complete tumour resection. We present a compact reflectance confocal microscope with a 20 mm working distance that provided <1.2 µm spatial resolution over a 600 µm × 600 µm field of view in the near-infrared region. A physical footprint of 200 mm × 550 mm was achieved using only standard off-the-shelf components. Theoretical performance of the optical design was first evaluated via commercial Zemax software. Then three specimens from rodents: fixed brain, frozen calvaria and live hippocampal slices, were used to experimentally assess system capability and robustness. Results show great potential for the proposed system to be translated into use as a next generation label-free and contactless neurosurgical microscope.

Resistance risk assessment for Fusarium graminearum to pydiflumetofen, a new succinate dehydrogenase inhibitor.

BACKGROUND: Pydiflumetofen is a new generation succinate dehydrogenase inhibitor currently undergoing the process of registration in China for the control of Fusarium head blight in wheat. A resistance risk assessment of Fusarium graminearum to pydiflumetofen was undertaken in this study. RESULTS: A total of 75 pydiflumetofen-resistant mutants were generated through spontaneous selection and displayed high resistance with an average resistance factor (RF) value of 78. Four mutants were generated through UV mutagenesis and displayed very high resistance with an RF value >1000. The sequence analysis results for Sdh genes and fitness studies revealed the existence of four types of mutations. In particular, 32 spontaneous selection mutants (SP mutants) had an arginine (R) to histidine (H) transition at position 86 in FGSdhC, resulting in seriously reduced fitness. Seven SP mutants had an R to cysteine (C) transition at position 86 in FGSdhC, resulting in reduced fitness. Thirty-six SP mutants had an alanine (A) to valine (V) transition at position 83 in FGSdhC and had no fitness penalties. The efficacy of pydiflumetofen towards a mutant carrying A83V in FGSdhC in vivo was significantly decreased at 42.7%. Four UV mutants had no mutations on all Sdh genes and no fitness penalties. Cross-resistance among boscalid, fluopyram and pydiflumetofen was observed. CONCLUSION: Sdhc mutations were found and other target site resistance may be present in laboratory PR mutants of F. graminearum. An overall moderate risk of resistance development in F. graminearum was recommended for pydiflumetofen. © 2019 Society of Chemical Industry.

High-Precision Indoor Visible Light Positioning Using Modified Momentum Back Propagation Neural Network with Sparse Training Point.

In this letter, we propose an indoor visible light positioning technique using a Modified Momentum Back-Propagation (MMBP) algorithm based on received signal strength (RSS) with sparse training data set. Unlike other neural network algorithms that require a large number of training data points to locate accurately, we have realized high-precision positioning for 100 test points with only 20 training points in a 1.8 m × 1.8 m × 2.1 m localization area. In order to verify the adaptability of the MMBP algorithm, we experimentally demonstrate two different training data acquisition methods adopting either even or arbitrary training sets. In addition, we also demonstrate the positioning accuracy of the traditional RSS algorithm. Experimental results show that the average localization accuracy optimized by our proposed algorithm is only 1.88 cm for the arbitrary set and 1.99 cm for the even set, while the average positioning error of the traditional RSS algorithm reaches 14.34 cm. Comparison indicates that the positioning accuracy of our proposed algorithm is 7.6 times higher. Results also show that the performance of our system is higher than some previous reports based on RSS and RSS fingerprint databases using complex machine learning algorithms trained by a large amount of training points.

25 mJ, 5 KHz, 3 ns, Nd:YAG discrete path slab amplifier using a hybrid resonator.

We report what we believe to be potential improved performance for a Nd:YAG discrete path slab amplifier configuration based on a hybrid resonator system. The amplifier is driven by a Q-switched 0.3 mJ nanosecond oscillator that generates an initial laser pulse at a repetition rate of 5 KHz and has beam quality of M2<1.3. The input pulse makes 12 passes through the slab amplifier to yield 25 mJ output pulse energy at the absorbed pump power of 878 W. A corresponding optical-to-optical efficiency of 14.3% was obtained, and the beam quality factors M2 in the unstable and stable direction were 1.7 and 1.5, respectively. No detectable signs of amplified spontaneous emission were observed.