Controllable optical bistability in a Fabry-Pérot cavity with a nonlinear three-dimensional Dirac semimetal

Optical bistability(OB)is capable of rapidly and reversibly transforming a parameter of an optical signal from one state to another,and homologous nonlinear optical bistable devices are core components of high-speed all-optical communication and all-optical networks.In this paper,we theoretically investigated the controllable OB from a Fabry-Pérot(FP)cavity with a nonlinear three-dimensional Dirac semimetal(3D DSM)in the terahertz band.The OB stems from the third-order nonlinear bulk conductivity of the 3D DSM and the resonance mode has a positive effect on the generation of OB.This FP cavity structure is able to tune the OB because the transmittance and the reflectance can be modulated by the Fermi energy of the 3D DSM.We believe that this FP cavity configuration could provide a reference concept for realizing tunable bistable devices.

A novel pathogen Fusarium cuneirostrum causing common bean(Phaseolus vulgaris)root rot in China

Several fungal pathogens cause root rot of common bean,among which Fusarium spp.are the most common pathogens causing Fusarium root rot(FRR)worldwide.FRR has been becoming an increasingly severe disease of common bean in China,but the species of Fusarium spp.have remained unclear.Thus,this study was performed to identify the pathogen causing common bean root rot in Liangcheng County,Inner Mongolia,China.Nineteen Fusarium-like isolates were obtained after pathogen isolation and purification.The pathogenicity test indicated that eight isolates caused severe disease symptoms on common bean,while 11 other isolates were not pathogenic.The eight pathogenic isolates,FCL1–FCL8,were identified as Fusarium cuneirostrum by morphological characterization and phylogenetic analysis using partial sequences of EF-1α,ITS,28S,and IGS regions.Host range test showed that the representative F.cuneirostrum isolate FCL3 was also pathogenic to mung bean,while not pathogenic to adzuki bean,chickpea,cowpea,faba bean,pea,and soybean.Moreover,50 common bean and 50 mung bean cultivars were screened for resistance to FRR,and seven highly resistant or resistant cultivars of common bean were identified,while no resistant cultivars of mung bean were screened.This study revealed that F.cuneirostrum was one of common bean FRR pathogens in Inner Mongolia and it could induce mung bean root rot as well.To our knowledge,this is the first report of F.cuneirostrum causing FRR of common bean in China.

Comparison of aerial and ground spraying applications in controlling fusarium crown rot in wheat

Fusarium crown rot (FCR) is a chronic disease in many regions of the world in wheat, caused by Fusarium culmorum, Fusarium pseudograminearum, and Fusarium graminearum. The operational efficacy of pesticide applications using unmanned aerial vehicles (UAVs) significantly affects the biological efficacy of the pesticides. This study aimed to compare the effectiveness of unmanned aerial vehicle and field sprayer applications in controlling crown rot diseases frequently observed in wheat crops in the Thrace region, Turkey. A licensed fungicide containing the active ingredients, prochloraz plus trifloxystrobin plus cyproconazole mixture was applied to wheat during the ZGS 27 growth stage. The disease severity, disease incidence, and the effectiveness of fungicide treatment on disease severity (%) were evaluated for F. culmorum crown rot disease. The results showed that the severity of the disease during the seedling stage was 11.25% and 18.33% for unmanned aerial vehicle and field sprayer applications, respectively. In the harvest stage, the incidence of disease was 28.33%-39.99% and 48.75%-51.25%, respectively, and the effectiveness of unmanned aerial vehicle application was found to be high, approximately 52%, during the seedling and harvest stages. The unmanned aerial vehicle, acting similarly to the field sprayer, exhibited higher grain quality under conditions of stress from disease. Furthermore, spike weight, grain weight, and number of grains exhibited stronger positive correlations compared to unmanned aerial vehicle treatment. Therefore, unmanned aerial vehicles have promising potential as viable options to manage FCR when the prevailing environmental conditions are not conducive to the use of field sprayer. The results of this research will guide future studies to investigate the efficacy of UAVs on a wider range of pesticides and to further develop the technology to investigate its effectiveness, cost-effectiveness, and sustainability in agricultural applications.

Genome-wide association mapping and genomic prediction of stalk rot in two mid-altitude tropical maize populations

Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.

Effective transmittance of Fabry–Perot cavity under non-parallel beam incidence

The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resonant cavity can be expressed by the Airy function. However, in reality, it is difficult to achieve perfect parallelism with collimated beams. In this article, a theoretical model is established for non-parallel light incidence, which assumes that the non-parallel incident light is a cone-shaped beam, and the cone angle is used to quantify the non-parallelism of the beam. The transmittance function of the FP resonant cavity under non-parallel light incidence is derived. The accuracy of the model is experimentally verified. Based on this model, the effects of divergence angle, tilt angle and FP cavity parameters(reflectivity, cavity length)on the ITF are studied. The reasons for the decrease in peak value, broadening and asymmetry of the interference peak under non-parallel light incidence are explained. It is suggested that a fine balance between the interference peak and the collimation effect of the incident light should be considered in the design and application of FP resonant cavities, especially for tilted applications such as angle-scanned spectroscopy. The research results of this article have certain significance for the design and application of FP resonant cavities.

Damage and Control Suggestions for the Emerging Disease Coffee Root Rot

[Objectives]The paper was to elucidate the symptoms,morphological characteristics,etiological factors,and current extent of damage associated with coffee root rot disease.[Methods]The symptoms,morphological characteristics,and etiological factors associated with coffee root rot disease were systematically observed,described,and analyzed.The assessment of damage was carried out using a specialized investigative methodology.[Results]The application of bottom fertilizer containing Fusarium incarnatum facilitated the pathogen's entry through root wounds during transplantation,resulting in the development of water-soaked depression lesions in the affected areas.This infection significantly reduced the number of lateral roots in coffee plants,leading to symptoms such as wilting,withering,and ultimately,the death of the aboveground foliage.F.incarnatum exhibited three distinct types of spore morphology:macroconidia,which were sickle-shaped;mesoconidia,which were spindle-shaped;and microconidia,which were oval-shaped.The incidence rate of the disease in the affected region reached 100%,with a disease index exceeding 91,indicating severe damage.[Conclusions]This study serves as a valuable reference for the prevention and management of the emerging disease known as coffee root rot.

New Rotative Radiofrequency Technology: A Multicenter Retrospective Study on Efficacy and Safety

Background: Non-ablative radiofrequency (RF) technology is widely used for the treatment of signs of aging, skin laxity, localized fat and cellulite. However, many RF devices suffer from technical limitations that make the results highly dependent on the user’s experience or clinical limitations that compromise safety, efficacy and comfort. Objective: To evaluate the efficacy and safety of a novel semi-automatic non-ablative RF device for skin tightening, body shaping and cellulite reduction. Materials and methods: A retrospective multicenter study was performed using a novel rotative RF device with temperature and impedance control (Sculpt&Shape®, Sinclair, Spain). 58 subjects underwent a minimum of 4 treatments every 1-2 weeks. A total of 120 treatments (56.7% body and 43.3% facial) and 1034 sessions were performed. Efficacy was evaluated by 3 researchers using the Global Aesthetic Improvement Scale (GAIS) and anthropometric measurements were collected. Subject and practitioner satisfaction were recorded. Safety was evaluated by analyzing the perception of pain during the treatment and the side and adverse effects immediately after treatment and over the next 48 hours. Results: Between 25% and 50% improvement was achieved according to the GAIS. Statistically significant (p < 0.01) abdominal fold reduction of 5.1 mm and circumference reduction of 32.0 mm, 16.4 mm and 13.9 mm were recorded for the abdomen, legs and arms, respectively. 77.5% of subjects and 94.9% of practitioners were either satisfied or very satisfied. Minor adverse effects were found in 0.97% of the sessions. Conclusion: This novel semi-automatic rotative RF device has been found to provide treatments that are effective, safe and comfortable for both practitioners and subjects. .

Influence of Microorganisms Effective against Basal Rot and on Agronomic Parameters of Onion [Allium cepa L. (Amaryllidaceae)]

Onions are a horticultural crop of great economic, dietary and medicinal importance, and are highly prized by the Ivorian population. However, production remains low, due to a number of constraints, including parasitic attacks. The most frequent is fusariosis caused by Fusarium sp., a pathogen that causes enormous damage to onion crops. Faced with these attacks, chemical control appears to be ineffective, with consequences for human health and the environment. This is why the search for effective alternative methods that respect the environment and human health is so necessary. It is in this context that this study was carried out, with the general aim of controlling fusarium wilt in onion crops, with a view to improving onion production in Ivory Coast through the use of effective microorganisms. The experimental set-up used for this purpose was a fisher block with complete randomization, comprising three replicates. A fungal spore concentration of 106 spore/mL of Fusarium sp., three doses (1%;2.5% and 5% v/v) of EM and one dose of a chemical fungicide (30 mL/16L) were tested on young onion plants. Each block consisted of nine sub-plots with nine treatments. Health parameters (incidence and severity) and agronomic parameters (growth and yield) were assessed. Microbiological analysis of the EM revealed the presence of nine morphotypes of Trichoderma sp., Aspergillus clavatus, Aspergillus flavus, Aspergillus sp., Penicillium sp., Rhizopus sp., lactic acid bacteria of the Bacillus family and the yeast Saccharomyces cerevisiae. Field experimentation showed that the 5% EM microbial solution reduced the incidence and severity of fusariosis compared with the chemical fungicide, and proved to be the best. This dose reduced yield losses by 7.14%, while improving onion growth and yield by over 5%. The results demonstrated the ability of the EM solution to effectively control the causal agent of basal rot in onion crops.

填充密度对非对称Fabry−Pérot纳米腔结构色色相和饱和度的影响

基于Fabry-Pérot(F-P)纳米腔创建的结构色,在高分辨率显示、高密度光学数据存储和防伪等领域有巨大的应用潜力。本研究针对包含不同底层金属材料和中间介质材料的四种非对称F-P纳米腔结构,保持纳米腔尺寸恒定,通过改变周期性纳米腔阵列的填充密度调控结构色的颜色属性,使用时域有限差分法(FDTD)分析探究了填充密度对色相和饱和度的影响。实验结果发现,通过改变填充密度可以有效实现对生成结构色的色相和饱和度的调控,提供了以固定的腔厚度扩展干涉结构色色域的自由度。本研究对使用非对称F-P纳米腔实现广色域、高饱和度和高分辨率的结构色有指导性意义。

基于大运中心重启ROT项目新机制PPP的相关研究

随着我国体育产业发展,体育场馆的兴建数量也逐渐增多。国家出台相关政策,鼓励现有的体育场馆采用ROT模式进行运营,引入社会力量对体育场馆进行改造、运营。但随着运营时间的深入,有不少社会力量由于各式的原因给未来的持续运营造成了不确定的影响,同时相关还在建的配套设施难以继续推进,造成ROT项目的停滞。本文以深圳大运中心为例,由于财务原因,该中心诸多在建未建的配套设施无法继续推进,ROT运营模式难以持续运营下去,鉴于此种情况,区政府计划终止与该集团签订的相关协议,决定采用政府和社会资本合作(PPP)模式,将大运中心主场馆运营权和配套服务设施的投资建设运营权捆绑,利用配套服务设施的经营收入,反哺大运中心主场馆的运营。拟为相关类似项目提供参考。

Enhancing Tomato (Solanum lycopersicum L.) Fruit Yield and Quality and Blossom End Rot Control Using Different Biological Calcium Sources

Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in susceptible cultivars, may cause severe economic losses. The goal of this study is to determine the effect of three organic calcium sources on the growth and quality of fruit production of tomatoes. Egg, snail and sea shell powders and extracts have been used as biological fertilizers. The experiment was conducted in a block factorial trial with three replications. The trials comprised two factors: calcium sources and calcium source form (powder and extract). The results showed that the growth parameters and yield were improved by the calcium source, whatever the form. Also, BER was lower in plants treated with calcium contrary to the control. However, plants treated with eggshells showed the best growth (mean) and the lowest rate (0.40%) of BER than the snail and sea shell.

Formulation of Biofungicides from Cymbopogon citratus and Tithonia diversifolia: Evaluating Its Antimicrobial Activities against Pythium myriotylum, the Causal Agent of Root Rot of Xanthosoma sagittifolium (L.) Schott

Three fungicide formulations, namely M1, M2 and M3, were prepared from sodium bicarbonate, citronella essential oil and sunflower slurry. The stability of M1, M2 and M3 formulations was determined based on pH, temperature, order of incorporation of the inputs and storage time. The most stable formulations were used for antagonistic tests on Pythium myriotylum. The Minimum Inhibitory Concentration (MIC) was used for the greenhouse tests and the mode of action was determined in vitro. The study showed that the order of incorporation of the inputs “Essential Oil-Tween 80-Bicarbonate-Slurry” (EO-T80-B-S) promotes stability. M1 and M2 are stable at 4°C, 25°C, 37°C and 40°C temperatures and have a pH of 7 and 8 respectively. The Minimum Inhibitory Concentration of M1 and M2 is 1% on P. myriotylum. M1 and M2 act on Pythium by membrane lysis, inhibiting proton pumps and inhibiting protein synthesis. The formulations M1 and M2 reduce the incidence of root rot disease in cocoyam plants growth in the greenhouse. M1 and M2 are potential candidates for improvement of cocoyam seedlings production in Cameroon.

Changes in concentrations and transcripts of plant hormones in wheat seedling roots in response to Fusarium crown rot

Fusarium crown rot(FCR) is a soilborne disease causing severe yield losses in many wheat-growing areas of the world. Diseased plants show browning and necrosis of roots and stems causing white heads at maturity. Little is known about the molecular processes employed by wheat roots to respond to the disease. We characterized morphological, transcriptional and hormonal changes in wheat seedling roots following challenge with Fusarium pseudograminearum(Fp), the main pathogen of FCR. The pathogen inhibited root development to various extents depending on plants' resistance level. Many genes responsive to FCR infection in wheat roots were enriched in plant hormone pathways. The contents of compounds involved in biosynthesis and metabolism of jasmonic acid, salicylic acid, cytokinin and auxin were drastically changed in roots at five days post-inoculation. Presoaking seeds in methyl jasmonate for 24 h promoted FCR resistance, whereas presoaking with cytokinin 6-benzylaminopurine made plants more susceptible. Overexpression of TaOPR3, a gene involved in jasmonic acid biosynthesis, enhanced plant resistance as well as root and shoot growth during infection.

Enhancing Tomato (Solanum lycopersicum L.) Fruit Yield and Quality and Blossom End Rot Control Using Different Biological Calcium Sources

Cultivated for its richness in nutrients, tomato culture is demanding fertilizer, especially in calcium. Calcium deficiencies and physiological disorders cause serious diseases in tomatoes. Blossom end rot (BER), in susceptible cultivars, may cause severe economic losses. The goal of this study is to determine the effect of three organic calcium sources on the growth and quality of fruit production of tomatoes. Egg, snail and sea shell powders and extracts have been used as biological fertilizers. The experiment was conducted in a block factorial trial with three replications. The trials comprised two factors: calcium sources and calcium source form (powder and extract). The results showed that the growth parameters and yield were improved by the calcium source, whatever the form. Also, BER was lower in plants treated with calcium contrary to the control. However, plants treated with eggshells showed the best growth (mean) and the lowest rate (0.40%) of BER than the snail and sea shell.

Colonization by Klebsiella variicola FH-1 stimulates soybean growth and alleviates the stress of Sclerotinia sclerotiorum

Sclerotinia stem rot,caused by Sclerotinia sclerotiorum,is a destructive soil-borne disease leading to huge yield loss.We previously reported that Klebsiella variicola FH-1 could degrade atrazine herbicides,and the vegetative growth of atrazine-sensitive crops(i.e.,soybean)was significantly increased in the FH-1-treated soil.Interestingly,we found that FH-1 could promote soybean growth and induce resistance to S.sclerotiorum.In our study,strain FH-1 could grow in a nitrogen-free environment,dissolve inorganic phosphorus and potassium,and produce indoleacetic acid and a siderophore.The results of pot experiments showed that K.variicola FH-1 promoted soybean plant development,substantially improving plant height,fresh weight,and root length,and induced resistance against S.sclerotiorum infection in soybean leaves.The area under the disease progression curve(AUDPC)for treatment with strain FH-1 was significantly lower than the control and was reduced by up to 42.2%within 48 h(P<0.001).Moreover,strain FH-1 rcovered the activities of catalase,superoxide dismutase,peroxidase,phenylalanine ammonia lyase,and polyphenol oxidase,which are involved in plant protection,and reduced malondialdehyde accumulation in the leaves.The mechanism of induction of resistance appeared to be primarily resulted from the enhancement of transcript levels of PR10,PR12,AOS,CHS,and PDF1.2 genes.The colonization of FH-1 on soybean root,determined using CLSM and SEM,revealed that FH-1 colonized soybean root surfaces,root hairs,and exodermis to form biofilms.In summary,K.variicola FH-1 exhibited the biological control potential by inducing resistance in soybean against S.sclerotiorum infection,providing new suggestions for green prevention and control.

Isolation and Identification of Pathogens Causing Foot Rot Disease of Bayinbuluk Sheep in Xinjiang

[Objective]The paper was to investigate the pathogenicity of Fusobacterium necrophrum in Bayinbuluk sheep of Xinjiang.[Method]The pathogens of 60 rotten limb tissue samples were isolated and identified from 2019 to 2021.The pathogenicity and bacteria were detected by using artificial infection test,bacterial identification instrument and high performance liquid mass spectrometer.[Result]A total of 3 pathogenic bacteria were isolated from foot rot disease of Bayinbuluk sheep,namely F.necrophrum,Staphylococcus aureus and Escherichia coli,indicating a mixed infection.All of the isolates could cause death in mice,and the fatality rate of mice was 50%.[Conclusion]Foot rot disease is more common in the Bayinbuluk sheep flock in Hejing County of Xinjiang,and the disease can be controlled effectively by doing a good job of sanitary disinfection in the enclosure.

Fungal community structure analysis of peanut pod rot in soil in Hebei Province,China

In recent years,peanut yield and quality are more seriously affected by pod rot disease in China.However,managing this disease has proven challenging due to the wide host range of its pathogens.In this study,four soil samples were collected from fields with pod rot disease in Hebei Province,and 454 pyrosequencing was used to analyze the fungal communities structure within them.All 38490 ITS high-quality sequences were grouped into 1203 operational taxonomic units,the fungal community diversity of four soil samples was evaluated and compared using Shannon index and Simpson index.The results showed that members of Ascomycota were dominant,followed by Basidiomycota.According to the BLAST results at the species level,Guehomyces had the highest abundance,accounting for about 7.27%,followed by Alternaria,Fusarium,and Davidiella.The relative abundance of Fusarium oxysporum isolated from rotting peanuts in soil with peanut rot was higher than that in the control,indicating that Fusarium oxysporum might be one of the main pathogenic fungus of peanut rot in this area.This study delved into the broader fungal community associated with peanut pod rot,providing a theoretical foundation for preventing and treating this disease in agriculture.

Occurrence Factors and Efficient Green Prevention and Control Technology of Peanut Stem Rot Caused by Sclerotium rolfsii in Southern Mountainous Area of Shandong Province

Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.

Effects of Torreya grandis Root Rot on Seedling Growth and Screening of Its Chemical Control Agents

[Objectives]This study was conducted to prevent the occurrence of root rot disease in Torreya grandis and improve the yield and quality of T.grandis.[Methods]One-year-old and two-year-old seedlings of Torreya grandis‘Xifei’and‘Cufei’were inoculated with the root rot pathogen Fusarium fujikuroi,and the changes in photosynthesis,chlorophyll content,malondialdehyde,and defense enzyme system(superoxide dismutase,peroxidase,and catalase)activity in leaves of T.grandis seedlings were investigated using water as a control.Meanwhile,the control effects of 80%carbendazim wettable powder,64%metalaxyl·mancozeb wettable powder,430 g/L tebuconazole suspension and 30%difenoconazole·cyproconazole EC on root rot in T.grandis were investigated.[Results]After inoculation with the pathogen F.fujikuroi,the net photosynthetic rates and transpiration rates in leaves of T.grandis‘Xifei’and‘Cufei’decreased,and the contents of chlorophyll decreased,while the contents of malondialdehyde increased,and the contents of superoxide dismutase and catalase increased with time.However,peroxidase showed a high activity in T.grandis‘Cufei’only,but a trend of"increasing-decreasing-increasing"in T.grandis‘Xifei’.Among the four chemical control agents,64%metalaxyl·mancozeb wettable powder had the best control effect on root rot of T.grandis caused by the pathogenic fungus F.fujikuroi.[Conclusions]The net photosynthetic rate,transpiration rate,chlorophyll content,malondialdehyde content,superoxide dismutase activity and catalase activity could all be used as screening indicators for T.grandis varieties resistant to root rot.Meanwhile,64%metalaxyl·mancozeb wettable powder could be used as a control agent for root rot on T.grandis.

Research Progress in Biological Control of Soft Rot of Amorphophallus konjac

In this paper,the main control methods of soft rot of Amorphophallus konjac are reviewed,with a focus on the current research status of using plant growth promoting rhizobacteria for biological control of soft rot of A.konjac,and future research directions are looked forward to.