Successive Seasons Research Articles

Antigenic drift and subtype interference shape A(H3N2) epidemic dynamics in the United States.

Influenza viruses continually evolve new antigenic variants, through mutations in epitopes of their major surface proteins, hemagglutinin (HA) and neuraminidase (NA). Antigenic drift potentiates the reinfection of previously infected individuals, but the contribution of this process to variability in annual epidemics is not well understood. Here, we link influenza A(H3N2) virus evolution to regional epidemic dynamics in the United States during 1997-2019. We integrate phenotypic measures of HA antigenic drift and sequence-based measures of HA and NA fitness to infer antigenic and genetic distances between viruses circulating in successive seasons. We estimate the magnitude, severity, timing, transmission rate, age-specific patterns, and subtype dominance of each regional outbreak and find that genetic distance based on broad sets of epitope sites is the strongest evolutionary predictor of A(H3N2) virus epidemiology. Increased HA and NA epitope distance between seasons correlates with larger, more intense epidemics, higher transmission, greater A(H3N2) subtype dominance, and a greater proportion of cases in adults relative to children, consistent with increased population susceptibility. Based on random forest models, A(H1N1) incidence impacts A(H3N2) epidemics to a greater extent than viral evolution, suggesting that subtype interference is a major driver of influenza A virus infection ynamics, presumably via heterosubtypic cross-immunity.

Antigenic drift and subtype interference shape A(H3N2) epidemic dynamics in the United States

Influenza viruses continually evolve new antigenic variants, through mutations in epitopes of their major surface proteins, hemagglutinin (HA) and neuraminidase (NA). Antigenic drift potentiates the reinfection of previously infected individuals, but the contribution of this process to variability in annual epidemics is not well understood. Here, we link influenza A(H3N2) virus evolution to regional epidemic dynamics in the United States during 1997—2019. We integrate phenotypic measures of HA antigenic drift and sequence-based measures of HA and NA fitness to infer antigenic and genetic distances between viruses circulating in successive seasons. We estimate the magnitude, severity, timing, transmission rate, age-specific patterns, and subtype dominance of each regional outbreak and find that genetic distance based on broad sets of epitope sites is the strongest evolutionary predictor of A(H3N2) virus epidemiology. Increased HA and NA epitope distance between seasons correlates with larger, more intense epidemics, higher transmission, greater A(H3N2) subtype dominance, and a greater proportion of cases in adults relative to children, consistent with increased population susceptibility. Based on random forest models, A(H1N1) incidence impacts A(H3N2) epidemics to a greater extent than viral evolution, suggesting that subtype interference is a major driver of influenza A virus infection ynamics, presumably via heterosubtypic cross-immunity.

Food supplementing peregrine falcon (Falco peregrinus tundrius) nests increase reproductive success with no change in mean parental provisioning rate.

Parents are expected to exhibit intermediate levels of investment in parental care that reflect the trade-off between current versus future reproduction. Providing parents with supplemental food may allow for increased care to the current brood (additive model), re-allocation of parental effort to other behaviours such as self-maintenance (substitution model), or may provide parents with a buffer against provisioning shortfalls (insurance model). We investigated the impact of parental food supplementation on provisioning behaviour and breeding success in Arctic-breeding peregrine falcons (Falco peregrinus tundrius) over five successive breeding seasons (2013-2017). We found that supplemental feeding had no impact on mean provisioning rates, yet resulted in increased nestling survival probability, increased nestling body mass and decreased variance in nestling body mass and provisioning rates. These results are consistent with parents adopting a hybrid of the additive and substitution models. We suggest that food supplementation enables increased investment in other forms of parental care (e.g. nest defence, brooding) without altering mean provisioning rates. The lack of observed effects on mean provisioning rates, coupled with increased survival and body mass of offspring, suggests a potential reallocation of parental effort. The findings contribute to understanding the responses of peregrine falcons to food supplementation, highlighting the need for future studies to explore broader environmental contexts and potential long-term effects on parental survival and future reproduction.

Gene action and hybrid vigour for yield, yield components and tolerance to the Two-Spotted Spider mite in summer squash

An investigation was conducted at Kaha Vegetable Research Farm in the Kaliobia Governorate from 2021 to 2023 with an aim to evaluate the performance of six inbred lines of summer squash and their fifteen crosses in both open field and plastic greenhouse conditions. The study spanned two successive summer seasons (2022 and 2023) and focused on assessing horticultural traits and resistance levels to the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). Significant variations were observed in the mean performance of all traits among different genotypes. Analysis revealed significant differences in both general (GCA) and specific (SCA) combining abilities for all studied traits, except for the number of days to anthesis of the first female flower, indicating the presence of both additive and non-additive gene effects in traits inheritance. In the plastic greenhouse, genotype P3 exhibited the highest resistance with an average of 10.6 mites per 2 inches², while the cross P2 × P6 showed tolerance with an average of 4.4 mites per 2 inches². This study highlights the potential of new summer squash hybrids with desirable horticultural traits and resistance to the two-spotted spider mite. Additionally, parent 222/2 (P1) demonstrated the best combining ability for all traits, while parents 264 (P5) and 240/3 (P4) were the most effective combiners for total yield. Breeders may leverage these parents for genetic enhancement and the production of hybrids with superior horticultural qualities. Overall, this research provides valuable insights for researchers, breeders and farmers involved in the cultivation, breeding and utilization of summer squash in Egypt.

Effect of insecticides and intercropping systems on fall armyworm (Spodoptera frugiperda (J.E. Smith)) infestations and damage in maize in northern Ghana

Field studies were conducted over two successive seasons to test the effects of maize-legume intercropping system on fall armyworm (FAW) (Spodoptera frugiperda (J.E. Smith)) and if insecticide use was necessary in intercropping systems. Three insecticide treatments [no spray, Emastar 112 EC (a.i. emamectin benzoate 48 g/L + acetamiprid 64 g/L), Neem seed oil (NSO) (a.i. 3% azadirachtin)] and three intercropping systems [sole maize (Zea mays L.), maize + soybean (Glycine max (L.) Merr.) and maize + groundnut (Arachis hypogaea L.)] were arranged as a 3 × 3 factorial experiment in a randomized complete block design. Data were collected on FAW larval infestations, parasitism rates, damage, grain yield and gross financial returns. Results from combined-years analyses showed that larval infestation was significantly affected by intercropping (p = 0.034) only, with maize + soybean recording the lowest infestation while sole maize was highest. Damage to crop and cobs were significantly affected by years and insecticide treatments. Cob damage was also significantly affected by intercropping system with maize + soybean being lowest and sole maize recording the highest damage. Parasitoids recorded were Coccygidium luteum, Chelonus bifoveolatus, and Charops sp. Grain yield was significantly affected by the intercropping systems only (p = 0.004), with no significant year (p = 0.152), insecticide (p = 0.726) and insecticide × intercropping system (p = 0.660) effects. Sole maize (1.6 t/ha) had the lowest yield while maize + groundnut (2.2 t/ha) was highest. In terms of income, an economic analysis showed that spraying intercropped maize with NSO resulted in the highest marginal rate of return. Thus, the use of NSO and intercropping is an effective FAW management strategy.

Response of Durum Wheat to Deficit Irrigation

Deficit irrigation trial has been conducted to see the response of durum wheat to the extent of deficit irrigation at Debre Zeit research center for three successive seasons from 2016 to 2018. Establishment irrigations were given for all plots after swing and irrigation water application events were monitored using long term meteorological data and soil moisture readings. Irrigation water application depths (amount of water applied) were calculated from cumulative crop evapotranspiration (ETc) values in a given period and plots were irrigated with depths that was replenish 100 %, 75%, and 50 % of the cumulative ETc as per the treatment to be applied. Measured amount of irrigation water applied to every plot measured by using 3 inch Parshall flume. Results indicated those grain yields significantly affected by deficit irrigation levels and furrow irrigation methods. The highest mean grain yield of 5.8 t/ha attained from 75% ETc irrigation level with alternate furrow irrigation method while the lowest mean yield of 3.989 t/ha was obtained from treatment irrigated with 50% ETc and conventional furrow irrigation method. Therefore, based on the current findings, the highest grain yield was obtained at 75% ETc with alternate furrow irrigation system while the highest WUE was recorded at irrigating 100% ETc with alternate furrow system.

Improving Fruit Set, Yield and Fruit Quality of Barhee Date Palms Using Some Natural Plant Extracts

This experiment was conducted during two successive seasons (2020 and 2021). The aim of this research is to study the effect of spraying Barhee date palm with some natural plant extracts on fruit set, yield and fruit physical and chemical properties. Inflorescences were sprayed with moringa and garlic extracts at 2 or 4% for both, three times (one hour before pollination, one month after pollination and two months after pollination). The obtained results indicated that spraying date palm inflorescences with moringa and garlic extracts produced higher initial fruit set as compared with the untreated ones in the two seasons. While all tested treatments improved fruit physical characteristics such as fruit weight, flesh weight, fruit length and diameter compared to the control treatment in the two studied seasons; moringa extract recorded the heaviest bunches and yield/palm in both seasons. In addition, the results showed that moringa extract at 4% increased total soluble solids%, total sugars%, reducing and non-reducing sugars% in both seasons compared to the control. Meanwhile, the lowest fruit set, bunch weight, yield/palm and fruit physical and chemical properties were recorded due to the control in both seasons. Also, all treatments reduced significantly total acidity% in both seasons. In addition, spraying moringa extract at 4% improved leaf mineral content (N, P, K, Ca and Mg) and gave the highest values followed by moringa extract at 2%, then garlic extract at 4% and 2%, respectively in both seasons.

Responses of Nutritional Status and Productivity of Timor Mango Trees to Foliar Spray of Conventional and/or Nano Zinc

The management of mango orchards is beset with a number of issues, including micronutrient deficits and significant fruit drop, which both contribute to decreases in mango tree output. Among these micronutrients, zinc is vital for increasing agricultural productivity, ensuring crop sustainability, and improving plant nutritional status during the growing season. To overcome zinc (Zn) deficiencies, this study was carried out during two successive seasons in an expected “Off” year (2022) and an expected “On” year (2023) on mature mango trees cv. Timor. To ameliorate this Zn deficiency, the effect of zinc in three forms—zinc oxide nanoparticles (ZnO NPs), sulfate (ZnSO4), and chelated (Zn-chelated)—as a foliar sprayon leaves’ mineral, chlorophyll, total carotenoids, and total carbohydrate contents and productivity were studied. Ten spray treatments were used in this study, including nano zinc (100 ppm), zinc sulfate (0.1%), and chelated zinc (0.2%) on two occasions, 7 January and 4 weeks after the first application, either alone or in combination with each other as compared to the control. In both study seasons, the results showed that all the zinc forms in mineral, chelated, or nano form had a positive effect on the number of flowers per panicle, the percentage of fruit set, the number of fruits per panicle, and the number of fruits per tree, and it decreased the percentage of fruit drop. Furthermore, all zinc forms significantly increased the leaf N, P, K, Ca, Mg, Cu, Fe, Mn, B, and Zn contents (%), and all the treatments improved the chlorophyll, total carotenoid, and total carbohydrate contents compared with the other treatments. The most effective treatment was two applications of nano zinc at 100 ppm in terms of the nutritional status and productivity of Timor mango trees.

Sport seasons through the lenses of project management – Identifying the common key characteristics of sport seasons and projects

There is a large amount of research on both successful project management and the management of professional sports organisations, but the relationship between these two phenomena remains to be analysed. Therefore, the aim of this article is to identify the similarities between sports seasons and projects by examining the characteristics of these two domains, as well as to lay the foundations for defining the potential management practices that can improve the efficiency of seasons using tools and techniques derived from project management. The results will be obtained through a narrative literature review of relevant books and articles on projects and sports seasons. The outcome of this research will contribute to a better understanding of how sport organisations can streamline their operations, optimise performance and ensure successful sport seasons by potentially implementing a project management approach.

Differences in the seasonal development of perithecia by Neonectria ditissima on apple trees across Northern Europe

AbstractAscospores discharged at rainfall and dispersed by wind can provide long-distance spread of the European canker fungus, Neonectria ditissima. Ascospores are produced by perithecia which are the sexual reproductive stage. Diffuse knowledge exists on the seasonal pattern of perithecium formation under different climatic conditions. Therefore, the development of perithecia was observed for several successive seasons at five sites in three Northern European countries. In Norway and Finland, ripe perithecia were commonly recorded throughout the year, and on individual cankers continuously for up to 28 months. In contrast, asexual reproductive structures (sporodochia) were confined to the growing season in both countries. In Northern Germany an average of 51% of cankers developed ripe perithecia by late winter, and perithecial senescence ensued in late spring. On average, ripe perithecia were present on cankers for 22 weeks. In contrast, sporodochia were observed all year round. The timing of perithecium maturation correlated with the number of days with > 2 mm rainfall in July–September. The presence of mature perithecia and sporodochia for different lengths of time in different countries has implications for regional disease management strategies.

Chitosan and riboflavin treatments affect marjoram growth, yield, and chemical composition

Background Marjoram is primarily cultivated to produce dried leaves and essential oil. Its active components have a wide range of biological and pharmacological activities in modern medicine. There is an interest in increasing marjoram production for local production and export. Chitosan (CH) and riboflavin (R) are required to promote plant growth and active ingredients. Objective The purpose of this study was to investigate how marjoram performance was affected by foliar spraying of CH and R at different concentrations. Materials and methods This investigation was performed over two successive seasons at two cuts. The used concentrations of CH were 100, 150, and 200 ppm, while R concentrations were 50 and 100 ppm. They were applied four times as a foliar spray to the vegetative growth during the growth season. At each harvest, the following parameters were recorded: fresh and dry weight, oil yield, total carbohydrates %, protein %, macronutrient content, total phenolics content, flavonoids content, antioxidant activity, and essential oil constituents to study their response to different treatments. Results and conclusion All the treatments of CH and R enhanced the vegetative growth, essential oil percentage, yield, active constituents, and oil components compared with untreated plants. Foliar application of CH at 200 ppm and R at 100 ppm increased plant growth, yield of volatile oil as well as chemical constituents compared with other treatments; however, CH was more effective than R. The combined application between CH and R resulted in the greatest values especially when both were applied at high doses.

Venous thromboembolism during three muslim pilgrimage seasons

Background Acute pulmonary embolism (PE) is a potentially fatal condition for which prompt recognition, risk assessment and appropriate treatment must be implemented to reduce mortality and morbidity. This study was planned to analyze all cases of venous thromboembolism (VTE) admitted to the tertiary care hospital during three successive Muslim hajj seasons. Methods A prospective observational study that included 135 patients of which 65 patients were with deep vein thrombosis (DVT group), 50 patients were with pulmonary embolism (PE group) and 20 patients were with concomitant DVT and PE (DVT/PE group). All patients were subjected to full history taking, clinical examination, laboratory, and radiological studies. Results The presentation with hemodynamic compromise and the percentage of mortality were more in patients with DVT/ PE compared to patients with PE alone. The patients in the DVT group had the highest D-dimer and triglyceride levels. The patients in the PE group had the most severe tachypnea and the highest values of cardiac biomarkers and aminotransferases. The patients in the DVT/PE group had the most rapid average pulse, the lowest average blood pressure, and the lowest oxygen saturation. Conclusions The presentations with DVT or DVT/PE were more in females and presentation with PE without DVT was more in males. Hajjis with VTE presented with less frequent symptoms, more overt clinical signs, more hemodynamic compromise and overall mortality compared to other studies. The study information may encourage the designated health authorities to raise awareness and implement VTE preventive measures during pilgrimage season.

EFFECT OF POTASSIUM SOURCES ON SOME POTATO CULTIVARS GROWN IN SANDY SOIL BY USING PIVOT IRRIGATION SYSTEM

Study was carried out during two successive summer seasons of 2021 and 2022 at private filed in El-Salhyia El-Gadida District, Sharkia Governorate, to study response of some potato cultivars to potassium sources as foliar application under sandy soil conditions using pivot irrigation system. This experiment included 25 treatments, which were the combinations between five potato cultivars (Spunta , Santana , Cara , Lady Rosetta and Hermes) and four potassium sources treatments , i.e. spraying with potassium silicate (KSil , (potassium citrate (KCit), potassium folvate (KF) and potassium thiosulpahte (KTS) as well as control (without spraying). These treatments were arranged in a split plot design with three replicates. Potato cultivars were randomly arranged in the main plots and potassium sources were randomly distributed in the sub plots. Spraying Cara cultivar with KCit increased number of tubers/ plant and total yield /hectare, whereas spraying Spunta cultivar with KCit increased average tuber weight in both seasons. While, spraying Hermes cultivar with KSil as foliar spray increased DM, starch and total carbohydrates in tubers. Spunta cultivar with water only increased total sugars in tubers. In addition, the fertilization of Cara cultivar with KCit as a foliar application recorded a relative increase in the total yield of tubers amounting to about 72.50% as an average of the two seasons compared to the same cultivar without.

Analysis of Spatial and Temporal Changes in FVC and Their Driving Forces in the Inner Mongolia Section of the Yellow River Basin

To investigate the spatial and temporal changes in fractional vegetation coverage (FVC) and their driving forces in different regions of the Inner Mongolia section of the Yellow River Basin, this paper observed the spatial trends and stability of FVC in these regions based on the MOD13Q1 information regarding the 2000–2020 period as a data source. It used the dimidiate pixel model to invert FVC, and based on the centre of gravity migration model, the coefficient of variation and the Mann–Kendall and Sen’s slope estimator test, it studied the spatial variation trend and stability of FVC in the four relevant areas of the Inner Mongolia section; an attribution analysis using a geodetector was also conducted. The following results were found: (1) in terms of temporal FVC change in the relevant areas, from 2000 to 2020, the overall FVC showed an increasing trend, indicating an obvious hierarchy of change as per different seasonal scales (summer > growing season > fall > spring). There is a mutation point in FVC in different areas, and the FVC sequence is random. (2) Regarding spatial change, the overall FVC showed a trend of being high in the eastern regions and low in the western regions and low–high–low from the north to the south; the stability of the Hetao Irrigation District–Wuliangsuhai Area changed more significantly with the successive seasons, and the degraded areas of FVC were mainly distributed in the city centre of the Kundulun River–Daheihe River Area and in the Hetao Irrigation District in the summer. (3) In terms of driving factors, soil type had a relatively higher explanatory power regarding the Hetao Irrigation District–Wuliangsuhai Area, rainfall had a relatively higher explanatory power regarding the Morin River–Wuding River Area and the Kundulun River–Daheihe River Area, and land use had a relatively higher explanatory power regarding the Ten Kongtui–Heidaigou Area.

Genome-wide association study of stem structural characteristics that extracted by a high-throughput phenotypic analysis "LabelmeP rice" in rice.

Stem is important for assimilating transport and plant strength; however, less is known about the genetic basis of its structural characteristics. In this study, a high-throughput method, "LabelmeP rice" was developed to generate 14 traits related to stem regions and vascular bundles, which allows the establishment of a stem cross-section phenotype dataset containing anatomical information of 1738 images from hand-cut transections of stems collected from 387 rice germplasm accessions grown over two successive seasons. Then, the phenotypic diversity of the rice accessions was evaluated. Genome-wide association studies identified 94, 83, and 66 significant single nucleotide polymorphisms (SNPs) for the assayed traits in 2 years and their best linear unbiased estimates, respectively. These SNPs can be integrated into 29 quantitative trait loci (QTL), and 11 of them were common in 2 years, while correlated traits shared 19. In addition, 173 candidate genes were identified, and six located at significant SNPs were repeatedly detected and annotated with a potential function in stem development. By using three introgression lines (chromosome segment substitution lines), four of the 29 QTLs were validated. LOC_Os01g70200, located on the QTL uq1.4, is detected for the area of small vascular bundles (SVB) and the rate of large vascular bundles number to SVB number. Besides, the CRISPR/Cas9 editing approach has elucidated the function of the candidate gene LOC_Os06g46340 in stem development. In conclusion, the results present a time- and cost-effective method that provides convenience for extracting rice stem anatomical traits and the candidate genes/QTL, which would help improve rice.

Effect of Crop Residue Management and Weed Management Practices on Nutrient Content and Nutrient Uptake in Wheat (Triticum aestivum L.).

The field experiment was carried out during two successive Rabi seasons of 2021-22 and 2022-23 at the Agronomy Research Farm of Acharya Narendra Deva University of Agriculture & Technology, Kumarganj, Ayodhya (U.P.).The treatment combinations of 4 crop residue management, viz. conventional tillage without residue, conventional tillage with residue (3 t/ha rice residue), zero tillage without residue, zero tillage with residue (3 t/ha rice residue) and 5 weed management practices, viz. Triallate 50% EC @ 1250 g a.i. ha-1, Triallate 50% EC @ 2500 g a.i. ha-1, Clodinafop propargyl 15% + Metsulfuron methyl 1% (60 g + 4 g a.i. ha-1), hand weeding at 20 and 40 days after sowing (DAS) and weedy check in wheat were tested with 3 replications in split-plot design, keeping crop residue management in main plots and weed management practices in subplots. Among the different crop residue management, zero tillage with residue was found most effective in maximizing nutrient content and nutrient uptake followed by conventional tillage with residue. Conventional tillage without residue showed lowest values of on nutrient content and uptake by crop. While in case of weed management practices hand weeding at 20 and 40 days after sowing (DAS) had a significant impact on maximizing nutrient content and nutrient uptake followed by post-emergence application of Clodinafop propargyl 15% + Metsulfuron methyl 1% (60 g + 4 g a.i. ha-1).

Improving Water Use Efficiency, Yield, and Fruit Quality of Crimson Seedless Grapevines under Drought Stress

Drought stress is a group of abiotic stresses that affects plant growth and yield production. A field experiment over two successive seasons (2021–2022 and 2022–2023) in sand soil was conducted to investigate the integration effect of deficit irrigation, soil amendment “hundzsoil”, and the spraying of proline on the water use efficiency (WUE), yield, and fruit quality of 8-year-old Crimson seedless table grapes. Four application rates of soil amendment (0, 2, 4, and 6 kg hundzsoil /vine) were added during the dormancy period, and four irrigation levels at 125, 100, 75, and 60% of the field capacity were applied just before flowering until harvest. Proline at two levels (0 and 500 ppm) was applied as a foliar spray. Parameters such as bud fertility, weight of 100 berries, juice volume, and cluster number were positively affected by irrigation at 75% FC along with applying hundzsoil at 2 and 4 kg/vine under proline spray in both seasons. Irrigation at the 125% FC level with a 6 kg hundzsoil application under proline spray resulted in the highest yield, berries number, cluster length, cluster weight, and total anthocyanin in both seasons. The TSS/acidity ratio was significantly and positively affected by deficit irrigation (60% FC level) under hundzsoil at a rate of 4 kg alongside proline spray. Reducing irrigation to 60% FC without hundzsoil and proline spray negatively affected numerous growth parameters and the yield. However, irrigation at 60% FC alongside 6 kg of hundzsoil and proline showed the highest IWUE in both seasons. Proline spray was a key factor in conserving water used for irrigation. This study recommends using deficit irrigation alongside hundzsoil application under proline spray as an adequate strategy for water use efficiency and improving the yield and fruit quality of Crimson seedless grapevines cultivated in sand soil.

Bacterial community and cyanotoxin gene distribution of the Winam Gulf, Lake Victoria, Kenya.

The Winam Gulf (Kenya) is frequently impaired by cyanobacterial harmful algal blooms (cHABs) due to inadequate wastewater treatment and excess agricultural nutrient input. While phytoplankton in Lake Victoria have been characterized using morphological criteria, our aim is to identify potential toxin-producing cyanobacteria using molecular approaches. The Gulf was sampled over two successive summer seasons, and 16S and 18S ribosomal RNA gene sequencing was performed. Additionally, key genes involved in production of cyanotoxins were examined by quantitative PCR. Bacterial communities were spatially variable, forming distinct clusters in line with regions of the Gulf. Taxa associated with diazotrophy were dominant near Homa Bay. On the eastern side, samples exhibited elevated cyrA abundances, indicating genetic capability of cylindrospermopsin synthesis. Indeed, near the Nyando River mouth in 2022, cyrA exceeded 10 million copies L-1 where there were more than 6000 Cylindrospermopsis spp. cells mL-1. In contrast, the southwestern region had elevated mcyE gene (microcystin synthesis) detections near Homa Bay where Microcystis and Dolichospermum spp. were observed. These findings show that within a relatively small embayment, composition and toxin synthesis potential of cHABs can vary dramatically. This underscores the need for multifaceted management approaches and frequent cyanotoxin monitoring to reduce human health impacts.

Antigenic drift and subtype interference shape A(H3N2) epidemic dynamics in the United States.

Influenza viruses continually evolve new antigenic variants, through mutations in epitopes of their major surface proteins, hemagglutinin (HA) and neuraminidase (NA). Antigenic drift potentiates the reinfection of previously infected individuals, but the contribution of this process to variability in annual epidemics is not well understood. Here we link influenza A(H3N2) virus evolution to regional epidemic dynamics in the United States during 1997-2019. We integrate phenotypic measures of HA antigenic drift and sequence-based measures of HA and NA fitness to infer antigenic and genetic distances between viruses circulating in successive seasons. We estimate the magnitude, severity, timing, transmission rate, age-specific patterns, and subtype dominance of each regional outbreak and find that genetic distance based on broad sets of epitope sites is the strongest evolutionary predictor of A(H3N2) virus epidemiology. Increased HA and NA epitope distance between seasons correlates with larger, more intense epidemics, higher transmission, greater A(H3N2) subtype dominance, and a greater proportion of cases in adults relative to children, consistent with increased population susceptibility. Based on random forest models, A(H1N1) incidence impacts A(H3N2) epidemics to a greater extent than viral evolution, suggesting that subtype interference is a major driver of influenza A virus infection dynamics, presumably via heterosubtypic cross-immunity.

Efficacy of different bioagents in suppressing Meloidogyne incognita, and evaluation of some physio-biochemical changes in Phaseolus vulgaris L.

Plant parasitic nematodes cause severe damage, reducing plant production. The ability of four various biocontrol agents was surveyed for effectiveness in inhibiting J2 of Meloidogyne incognita in vitro. The study aims to explore the impact of different bio-agents (Bacillus cereus 54-1, Streptomyces erythrogriesus sub sp. 2, Pleurotus ostreatus, and Spirulina platensis) on the root-knot-nematode, M. incognita reproduction, and their influence on plant growth as well as physiological and biochemical parameters in Phaseolus vulgaris L. plants under greenhouse conditions. Effective inoculation of four bio-control agents on growth and physio-biochemical parameters of bean plants infected with root-knot-nematode was also investigated. After 48 hours of exposure to bioagents, mortality was caused by M. incognita J2s. Mortality ranged between 67.3 and 89%. Under experimental conditions, further validating the relative efficacy of different bioagents in control M. incognita on common bean in two successive seasons. All pageants were efficient in preventing nematode reproduction, but with varying efficacy. Oxamyl (Nematicide) was an extremely effective treatment for suppressing total nematode populations. Nevertheless, the second most effective treatment for reducing M. incognita in roots and soil was B. cereus. All treatments significantly enhanced growth as compared to the control. Treatments with four bioagents significantly reduced H2O2 and malondialdehyde levels. While it significantly raised the activity of peroxidase, polyphenol-oxidase, and superoxide dismutase, in addition to raising the content of phenolics and flavonoids in the infected common bean. The tested bioagents were efficient in preventing nematode reproduction, but at various levels of efficacy. In addition, all treatments significantly enhanced common bean growth parameters and reduced the levels of both H2O2 and MDA. While it raised the activity of POD, PPO, SOD, and contents of phenolics and flavonoids in the infected common bean. These results highlight the value of bioagents as a promising biocontrol technique to manage root-knot-nematodes in common beans.