Incubation Period Research Articles

SVLIAR age-of-infection and -immunity structured epidemic model of COVID-19 dynamics

Stability analysis of nonlinear age-of-infection and -immunity structured SVLIAR-type model of susceptible, vaccinated, latent, COVID-19 infected, asymptomatic and recovered sub-classes of population dynamics is carried out in this paper. The SVLIAR model uses five age variables - age of vaccine immunity of vaccinated individuals, age of virus infection in organism during incubation period of latent individuals, “age” of infectious disease treatment of infected individuals, age of asymptomatic infectious dis-ease of asymptomatic individuals, “age” of immunity of organism after recovering of recovered individuals. Individuals can move from one subclass to another when these age variables take some fixed values, that is the processes in sub-classes are adjusted and synchronized by age variables. The conditions for the existence of disease-free and unique endemic equilibria and their local asymptotic stability were obtained. The local asymptotic stability/instability of endemic equilibrium of SVLIAR model is defined by criterion, which relates the demographic characteristics of population, infection disease characteristics (disease-induced death rate, death rate induced by the complications after disease), characteristics of vaccination (fraction of fully vaccinated susceptibles per unit of time, vaccination efficacy) and characteristics of age variables (their maximum values) of sub-classes. These theoretical results help understand better the conditions of transmission dynamics of the COVID-19 induced disease.

Evaluation of soil microbial activity after application of Paenibacillus polymyxa-based biofertilizer in wheat field experiment

The establishment of eco-friendly principles in agriculture requires, from one side, a reduced dependence on chemical fertilizers, pesticides and herbicides, and on the other, a maintenance of consistent yield and high plant productivity. Such substantial shift in the contemporary agricultural practices can be achieved only if a wide variety of alternative options is available. Furthermore, in order to become part of agricultural practices these options have to be affordable in a broad scale and effective against the loss of biodiversity and reduced soil fertility. The current study presents data about the metabolic activity and microbial community` structure in two soil samples – one treated with chemical fertilizer and another treated with chemical fertilizer reduced by 25% dose and supplemented with commercially available biofertilizer. Metabolic activity and properties of microbial soil communities were assessed by the BIOLOG® EcoPlate technique. The estimated parameters included average well-color development (AWCD) and utilisation of six guilds of substrates. Several functional indexes that are used for evaluation of community diversity and evenness were also estimated. The AWCD, expressed either as total activity or as guilds utilisation during the EcoPlate incubation period of seven days did not reveal significant difference between variants. However, most of the estimated functional indexes consistently indicated higher microbial diversity and more balanced structure of microbial community in the biofertilizer-supplemented variant. The results clearly implied that the biofertilizer based on nitrogen-fixing bacteria can positively influence the structure of soil communities and its application could be beneficial for soil fertility and plant productivity. Keywords: diazotroph, biofertilizer, BIOLOG® EcoPlate, functional indexes, metabolic activity, microbial communities

A novel indicator in epidemic monitoring through a case study of Ebola in West Africa (2014-2016).

The E/S (exposed/susceptible) ratio is analyzed in the SEIR model. The ratio plays a key role in understanding epidemic dynamics during the 2014-2016 Ebola outbreak in Sierra Leone and Guinea. The maximum value of the ratio occurs immediately before or after the time-dependent reproduction number (Rt) equals 1, depending on the initial susceptible population (S(0)). It is demonstrated that transmission rate curves corresponding to various incubation periods intersect at a single point referred to as the Cross Point (CP). At this point, the E/S ratio reaches an extremum, signifying a critical shift in transmission dynamics and aligning with the time when Rt approaches 1. By plotting transmission rate curves, β(t), for any two arbitrary incubation periods and tracking their intersections, we can trace CP over time. CP serves as an indicator of epidemic status, especially when Rt is close to 1. It provides a practical means of monitoring epidemics without prior knowledge of the incubation period. Through a case study, we estimate the transmission rate and reproduction number, identifying CP and Rt = 1 while examining the E/S ratio across various values of S(0).

Exploring microstructure variations and hydrogen storage characteristics in TiVNbCrNi high-entropy alloys with different Ni incorporation

In recent years, high-entropy alloys (HEAs), as a novel class of hydrogen storage materials, have been deemed highly promising due to their extensive compositional tunability and the unique high entropy effects. This study aims to enhance the comprehensive hydrogen storage performance of the TiVNbCr-based HEA by introducing Ni. The effects of Ni addition on the microstructural evolution of the alloy and its impact on activation properties, hydrogen absorption and desorption kinetics, thermodynamics, and cycling performance under the complex physicochemical environment of multiple principal elements was systematically investigated. The findings indicate that Ni addition shortens the activation incubation period of the alloy but more Ni reduces the intrinsic hydrogen absorption kinetics. In the Ti25V30Nb10Cr33Ni2 alloy, a high reversible hydrogen storage capacity of up to 2.2 wt% at room temperature was achieved, surpassing most of the currently reported body-centered cubic (BCC)-structured high-entropy hydrogen storage alloys. Furthermore, the influence of Ni on the alloy's hydrogen desorption kinetics and cycling hydrogenation performance was studied. Results from 110 cycles of testing reveal that the introduction of Ni-induced Laves phases can act to relax stress, thereby reducing strain accumulation during the hydrogen absorption and desorption cycling process. This could provide guidance for the design of high-entropy hydrogen storage alloys with extended cycling lifetimes.

Brucella Prostatitis: A Rare Manifestation of Fever of Unknown Origin, Detected by FDG PET/CT.

FDG PET/CT is a well-documented imaging investigation to evaluate fever of unknown origin (FUO). Brucellosis is one of the causes of FUO, which can be missed as it requires a longer incubation period for growth on culture media. Rarely, it can involve the prostate. Here, we present a case of FUO with initial negative blood and urine cultures and no localizing signs or symptoms. 18F-FDG PET/CT revealed hypermetabolism in the prostate and seminal vesicles. A repeat blood and urine culture showed the growth of Brucella species after 5 days of incubation, and the patient responded to Brucella-directed antibiotic therapy.

Effect Local Microorganisms Coconut Pulp in Increasing The Resistance of Red Chilli Plants To Fungus Colletotrichum acutatum J.H. Simmonds

The fungus Colletotrichum acutatum which often attacks chili plants causes anthracnose disease. Farmers generally use fungicides to control this disease. Continuous use of synthetic fungicides will have negative impacts. Plant extracts as an alternative to natural fungicides can be an appropriate and environmentally friendly choice. One of them is the use of Local Microorganisms (MOL). This research aims to determine the optimal concentration of coconut pulp MOL in increasing the resistance of red chilli plants to the fungus Colletotrichum acutatum that causes anthracnose disease. The study used a Totally Randomized Design (CRD) with 6 drugs, namely A (0 ml/water), B (5 ml/water), C (10 ml/water), D (15 ml/water), E (20 ml/water). ml/water), F (25 ml/water). There are four treatments each time. Information was broken down using ANOVA and continued with the Fair Genuine Contrast (BNJ) test at the 5% level (α = 5%). with a level of 5% (α = 5%). The results showed a significant effect on fungal colony diameter, germination period, plant height, plant incubation period, and disease severity. The best concentration of local coconut pulp microorganisms in inhibiting anthracnose disease was 25 ml/l water.

Second Language Attrition and The Savings Paradigm: An exploration of long-term retention of a minority language learned in an educational context.

Explorations of attrition attempt to gain insight into linguistic representations in the brain and to understand what supports the consolidation of information in memory so that language knowledge is retained, even after long periods of language disuse. In this study the role of extra-linguistic factors in influencing levels of knowledge retention over a long period of incubation is investigated along with the question if support for savings can be found, i.e., is seemingly forgotten knowledge in fact still intact and, therefore, may be accessed again. Four adults from Ireland currently living in Germany who had not had contact with the Irish language in approximately 30 years were tested on their knowledge of Irish lexical items and interviewed in depth on their experiences of learning Irish. Understanding language loss has important implications for the L2/FL education domain and pedagogy. If it can be established what impacts greater retention of knowledge, teaching curricula and methodologies can be revised accordingly to make them more effective with respect to long-term knowledge retention.

Synthesis and antimicrobial behaviour of NiO/Ag-based material

The main objective of the present work is the green synthesis of NiO and Ag nanoparticles using the leaf extract of Azadirachta indica and the development of NiO/Ag-based nanocomposites via an ultrasonic process. The synthesised NiO/Ag was characterised using different analytical methods and used as an antimicrobial agent against different bacterial and fungal strains. The antimicrobial study was done using the well diffusion method. The FTIR study indicated the presence of O–H, C–H (methylene or methyl), CO, O–H, and Ni–Ag, Ag–O, or Ni–O bonds on the surface of NiO/Ag. The XRD peaks of NiO/Ag were found to be 31.60 (103), 37.30 (111), 38.10 (111), 43.40 (200), 62.90 (220), 76.50 (008), 77.50 (311), and 79.50 (222), respectively. The maximum zones of inhibition were found to be 21.6 (±0.71), 21.2 (±0.69), 17.9 (±0.39), 13.3 (±0.81), and 12.3 (±0.38) mm against Escherichia coli, Staphylococcus aureus, Salmonella enterica, Candida albicans, and Aspergillus niger after incubation periods. On the basis of these findings, we can conclude that NiO/Ag is a potent antimicrobial agent against a variety of bacterial and fungal species.

Characterization of Alternaria blotch disease of apple in Himachal Pradesh, India: insights on morphology, pathogenicity, and molecular features.

Alternaria blotch disease in Himachal Pradesh, India, caused by Alternaria spp., adversely affects apple cultivars, resulting in reduced fruit size and quality accompanied by premature leaf fall. Sixteen Alternaria isolates from apple growing regions underwent comprehensive analysis including morphology, pathogenicity, and molecular characterization. Variations in conidiophore and conidia dimensions, shapes, and divisions were observed among isolates. Pathogenicity assays revealed differences in incubation periods, latent phases, and disease responses. Molecular characterization via nuclear ITS rDNA and RAPD analysis indicated 99-100% homology with Alternaria alternata, Alternaria mali, and other Alternaria spp., with a close phylogenetic relationship to Chinese isolates. Differentiation of isolates based on origin, cultural characteristics, and morphology was achieved using RAPD markers. The study identifies diverse genotypes and morphotypes of Alternaria contributing to apple blotch disease in Himachal Pradesh. These findings highlight the complexity of the pathogenic environment and hold significant implications for disease management in apple orchards.

Effects of polypropylene films and leached dissolved organic matters on bacterial community structure in mangrove sediments

Over the past decades, the accumulation of plastics in mangrove ecosystems has emerged as a significant environmental concern, primarily due to anthropogenic activities. Polypropylene (PP) films, one of the plastic types with the highest detection rate, tend to undergo intricate aging processes in mangrove ecosystems, leading to the release of dissolved organic matter (DOM) that may further influence the local bacterial communities. Yet, the specific effects of new and weathered (aged) plastic films and the associated leached DOM on bacterial consortia in mangrove sediments remain poorly understood. In this study, an incubation experiment was conducted to elucidate the immediate effects and mechanisms of the new and relatively short-term (45 or 90 days) aged PP films, as well as their leached DOM (PDOM), on characteristics of DOM and the bacterial community structure in mangrove sediments under different tidal conditions. Surface morphology and functional group analyses showed that both new and aged PP films exhibited comparable degradation profiles under different tidal conditions over the incubation period. As compared to the new PP film treatments, the introduction of the short-term aged PP films significantly affected the content of humic-like compounds in sediments, and such effects were partially ascribed to the release of PDOM during the incubation. Although the addition of PP films and PDOM showed minor effects on the overall diversity and composition of bacterial communities in the sediments, the abundance of some dominant phyla exhibited a growth or reduction tendency, possibly changing their ecological functions. This study was an effective attempt to investigate the relationship among plastic surface characteristics, sedimentary physicochemical properties, and bacterial communities in mangrove sediments. It revealed the ecological ramifications of new and short-term plastic pollution and its leachates in mangrove seedtimes, enhancing our understating of their potential impacts on the health of mangrove ecosystems.

Biodegradation of polypropylene plastics in vitro and natural condition by Streptomyces sp. isolated from plastic-contaminated sites

Most plastic degradation studies are conducted under controlled laboratory conditions. The current study investigated the ability to degrade Polypropylene (PP) plastic by Streptomyces ardesiacus strain NBI0111 under both laboratory and natural conditions. This strain exhibited the ability to degrade PP when cultured in BH medium and using PP plastics as carbon sources. After a 90-day incubation period, the weight loss of PP plastics reached 17.52 % (p < 0.05). The surface of the PP plastic showed significant changes compared to the control group. Chemical changes in the plastic were also detected on the 60th and 90th days, as confirmed by FTIR and GC-MS analyses. This strain was applied to degrade PP plastic in soils under natural conditions. Strain NBI0111 also resulted in a notable weight loss. The biodegradation test group exhibited a significant 12.5 % decrease compared to only a 3.88 % decrease in the control group (p < 0.05). Furthermore, a strong positive correlation between the weight loss of PP plastic cups and the density of microbial populations was observed. The capabilities demonstrated by Streptomyces ardesiacus strain NBI0111 in this study hold great promise for on-site plastic remediation, offering a sustainable solution to the problem of plastic pollution in the future.

Thermal image evaluation of crop diseases in the incubation period.

Early blight is one of the main diseases that causes serious pepper yield and quality reduction. The identification of the presymptomatic features during the incubation period is of great research significance, in that scientific prevention measures in the incubation period may effectively reduce the loss of peppers. The present study confirms the feasibility of the identification of presymptomatic features in pepper early blight by infrared thermography during the incubation period. The infrared thermal images of pepper blades were captured during the whole incubation period in our experiment. Evaluation parameters such as temperature uniformity (U) and the variation coefficient (C) were established by infrared thermal images for the blade temperature field. Evaluation parameters such as temperature uniformity U and variation coefficient C of pepper blades change during the time from being inoculated to significant morbidity. For cases of stabbing inoculation, there were no relatively obvious symptoms in visible light images until 96 h after inoculation, whereas some presymptomatic features appeared in infrared thermal images at 60 h after inoculation. Based on the uniformity changes (δU) and the variation coefficient changes (δC) in the temperature field distribution, the characteristic polynomial (CP)-GBDT model has been established by optimizing the gradient boosting decision tree (GBDT) model. Compared with the GBDT mode, the CP-GBDT model accuracy increased from 87.5% to 91.7% on the test set. Evaluation parameters such as temperature uniformity U and variation coefficient C can be used to effectively characterize the presymptomatic features of pepper early blight by infrared thermography during the incubation period. The results of the present study can provide a reference for the detection of crop diseases in the incubation period. © 2024 Society of Chemical Industry.

Improving quality of stored Trichogramma evanescens (Hymenoptera: Trichogrammatidae) by inducing diapause or quiescence

BackgroundEfficacy of parasitic wasps from the genus Trichogramma to attack the eggs of numerous important pests in various agricultural crops makes them one of the most prevalent biocontrol agents. In Trichogramma, the pre-pupal stage can survive during the cold season in a dormant state (diapause or quiescence). The optimal conditions for the induction of this pause of development during mass rearing to store the parasitoid for a long time in good quality depend on the species. In the present study, four factors [the incubation periods (24 and 48 h), diapause induction temperatures (9 and 11 °C), durations of the diapause induction (from 0 to 6 weeks), and the periods of storage (from 0 to 6 months)], were experimented to force Trichogramma evanescens Westwood, reared on Sitotroga cerealella, to enter diapause or quiescence and estimating their impacts on the efficacy of stored parasitoid.ResultsResults confirmed that the life parameters of T. evanescens as the percentage of adult emergence, female percentage, rates of wing deformation of emerged adults, and fecundity of emerged females were significantly affected by all experimented factors. The pre-storage treatments made it possible to store the parasitoid for at least 2 months at 3 °C, with no much changes in their fitness, the emergence rate of adults reached more than 80%, and the egg-laying efficacy of females reached more than 42 eggs per emerged female, when diapause induction treatments were applied for 5 weeks at 11 °C after 24 h of incubation. Furthermore, there is the possibility of storage for 6 months with an acceptable level of parasitoid’s quality, when diapause induction treatments were applied for 5 weeks at 9 °C after 24 h of incubation, the emergence rate reached 70%, and the number of eggs per female was 52 eggs, while no emergence of adult insects was recorded after 3 months of cold storage without diapause induction treatments.ConclusionTwo storage programs were reached for T. evanescens (depending on the adult emergence rate and fecundity of emerged females). There is a long-term storage (6 months), when diapause was induced at a low temperature (9 °C) after 24 h of incubation. Short-term storage (from 2 to 4 months), when quiescence was induced under a higher temperature of 11 °C after both 24 and 48 h of incubation.

Estimating the expression levels of genes controlling biofilm formation and evaluating the effects of different conditions on biofilm formation and secreted aspartic proteinase activity in Candida albicans and Saccharomyces cerevisiae: a comparative study

BackgroundCharacterization of yeast virulence genes is an important tool for identifying the molecular pathways involved in switching yeast virulence. Biofilm formation (BF) and secreted aspartic proteinase (SAP) activity are essential virulence factors that contribute to yeast pathogenicity.ResultsFour Candida albicans and two Saccharomyces cerevisiae strains were tested for BF and SAP activity under optimum conditions, and the expression levels of several genes controlling BF were quantified under the optimal conditions. Biofilm formation was assessed by the microplate method at different pH values, incubation times and culture media. Similarly, SAP activity was assessed at different pH values and incubation periods. The expression levels of nine genes were determined via qRT-PCR technique. All tests were carried out in triplicate, and the values presented as the means ± standard deviations and were analysed with the SPSS programme. Only C. albicans (1), C. albicans (2) and S. cerevisiae 43 formed biofilms. The optimal BF was obtained after culture in sabouraud dextrose broth with 8% glucose at pH 7.5, 4 and 6, respectively, for 48h. Candida albicans biofilm production was more significant than that of S. cerevisiae 43. Moreover, the SAP activity was estimated under the optimum conditions. All yeasts showed optimal SAP activity at pH 4, but astonishingly the SAP activity of S. cerevisiae 44 was higher than that of C. albicans. The expression levels of EFG1 and ZAP1 (transcription factors); ALS3, HWP1and YWP1 (adhesion genes); SAP1 and SAP4 (aspartic proteinase) in C. albicans (1); and FLO11 (adhesion gene) and YPS3 (aspartic proteinase) in S. cerevisiae 43 were quantified during biofilm development at different time intervals. The expression levels of EFG1, ALS3, YWP1, SAP1, SAP4, FLO11 and YPS3 were upregulated at 8 h, while that of ZAP1 was upregulated at 48 h. Only HWP1 was downregulated.ConclusionsThe findings of the present study may provide information for overcoming yeast BF and pathogenicity by regulating specific genes at specific times. Additionally, this study revealed the virulence of the commensal S. cerevisiae, which may take the pathogenicity direction as C. albicans.

Impact of Nest Parameters and Vegetation on Turtle Reproductive Success in the Araguaia River

Objective: The objective of this work is to verify whether these factors influence the hatching of Amazon turtle eggs in this region. Method: For this, data from reproductive periods during the years 2013 and 2019 were used within the selected areas. Only the depth of the nests was related to the total number of eggs, on both beaches, in both years, and with the number of eggs hatched, only on Praia da Saudade in 2013. Results and Conclusion: In 2019, Praias da Saudade and Thaís showed differences between incubation temperature, percentage of finer grains in the sand, distance from vegetation to nests and hatching rate. However, none of the evaluated parameters were related to reproductive success. Factors such as the incubation period, the amount of clay in the sand and the percentage of riverine vegetation may also be possible predictors of reproductive success that should be investigated.

Age-Stage, Two-Sex Life Table of an Alarming Quarantine Pest Trogoderma granarium on Stored Products

Trogoderma granarium (Coleoptera: Dermestidae) is a polyphagous pest of stored products and an alarming threat to food security around the globe. The current study is designed to construct the life table of T. granarium on four stored products, i.e., wheat, barley, rice, and maize at controlled conditions (33±1°C, 65% RH, and a photoperiod of 14 : 10 (L:D) h). The incubation period of T. granarium was longer (5.13 d) on maize and shorter (4.30 d) on wheat. The developmental period of 1st, 2nd, 3rd, and 4th larval instars of T. granarium was longer on maize than the other three hosts were significant. Statistical difference between the longevity of females and males was recorded, while no statistically significant difference was found in the preoviposition period. The mean fecundity values observed on wheat, barley, rice, and maize were 31.33±1.62, 26.21±1.49, 28.00±1.35, and 25.58±1.13, respectively. The highest fertility was observed in wheat and the lowest in maize. The net reproductive rate (R0) of T. granarium ranged from 8.66±2.86, 13.16±2.65, 12.53±2.27, and 10.23±2.32 offsprings on wheat, barley, rice, and maize, respectively. The highest gross reproductive value (GRR) was for T. granarium reared on barley (18.31±4.10/d), and the lowest was for maize (15.35±2.95/d). To complete the development, T. granarium took 48.97±0.68 d on maize, significantly higher than on other treatments (p&lt;0.05). The mean generation time (T) of T. granarium was considerably affected by tested products. Based on the results of the present study, maize is a less favorable diet for the development and reproduction of T. granarium and may be considered for the management of this detrimental pest.

Cloning, expression and purification of cellobiohydrolase gene from Caldicellulosiruptor bescii for efficient saccharification of plant biomass

Anthropogenic activities have led to a drastic shift from natural fuels to alternative renewable energy reserves that demand heat-stable cellulases. Cellobiohydrolase is an indispensable member of cellulases that play a critical role in the degradation of cellulosic biomass. This article details the process of cloning the cellobiohydrolase gene from the thermophilic bacterium Caldicellulosiruptor bescii and expressing it in Escherichia coli (BL21) CondonPlus DE3-(RIPL) using the pET-21a(+) expression vector. Multi-alignments and structural modeling studies reveal that recombinant CbCBH contained a conserved cellulose binding domain III. The enzyme's catalytic site included Asp-372 and Glu-620, which are either involved in substrate or metal binding. The purified CbCBH, with a molecular weight of 91.8 kDa, displayed peak activity against pNPC (167.93 U/mg) at 65°C and pH 6.0. Moreover, it demonstrated remarkable stability across a broad temperature range (60–80°C) for 8 h. Additionally, the Plackett-Burman experimental model was employed to assess the saccharification of pretreated sugarcane bagasse with CbCBH, aiming to evaluate the cultivation conditions. The optimized parameters, including a pH of 6.0, a temperature of 55°C, a 24-hour incubation period, a substrate concentration of 1.5% (w/v), and enzyme activity of 120 U, resulted in an observed saccharification efficiency of 28.45%. This discovery indicates that the recombinant CbCBH holds promising potential for biofuel sector.

Nanoparticles of Zinc Oxides Mitigated N2O Emissions in Tea Plantation Soil

The excessive application of nitrogen in tea plantations leads to severe soil acidification and N2O emission boosting. To promote sustainable agriculture, nanoparticles (NPs) have emerged as alternative fertilizers, but their effects on soil nitrification and greenhouse gas emissions in tea plantations remain unclear. In this study, the effects of NP type (ZnO-NPs and Fe2O3-NPs) and dose (0, 1, 10, and 100 mg·kg−1) on soil N2O emissions were investigated via a lab incubation trial. Soil pH, ammonium, and nitrate changes were also monitored during the incubation period. The abundance of functional genes related to nitrification and denitrification processes was analyzed as well. The results showed that ZnO-NPs led to a decrease in N2O emissions. The reduction effect was stronger with increasing dose and resulted in a 33% reduction at an addition rate of 100 mg·kg−1. The cumulative N2O emissions had significantly positive correlations with NH4+-N and NO3−-N. ZnO-NP addition showed a significantly negative effect on Ammonia-Oxidizing Archaea (AOA) but a positive effect on Ammonia-Oxidizing Bacteria (AOB) gene abundance. In contrast, Fe2O3-NPs showed an insignificant impact on N2O emissions and soil N content, as well as nitrification–denitrification gene abundance, regardless of different doses. These results imply that the application of ZnO-NPs may inhibit nitrification through the retarding of AOA activity. This study provided us with a potential practice to reduce N2O emissions in tea plantations by applying ZnO-NPs, but the efficiency of this reduction needs further examination under ambient conditions before field application.

Control biológico de Ralstonia solanacearum y su efecto en el crecimiento vegetativo de banano orgánico

The banana (Musa AAA) is one of the main economically important crops worldwide. Currently, it faces a serious problem of plant death caused by the bacterium Ralstonia solanacearum (Smith) variety 2. The objective of this research was to evaluate the effect of biological control of Moko disease and its relationship with the vegetative growth of banana seedlings under field conditions. Four treatments were employed: absolute control (T0), Trichoderma spp. (T2), Bacillus spp. (Bio-remedy) (T3), and ADMF® (T4) with three replications in a completely randomized block design. The incubation period, the incidence percentage, and the area under the disease progress curve (AUDPC) were evaluated, along with plant survival and height, pseudostem diameter, and leaf emission rate. At 113 days after transplanting (dat), treatments T1, T2, and T3 showed higher seedling survival. Plant height (111-145 cm), pseudostem diameter (7.43-11.28 cm), and leaf emission rate (11.74-13.15 leaves) exhibited significant differences among treatments. Treated plants showed the lowest AUDPC (between 576.1 and 1435.4 units) compared to untreated plants (3156.55 units). Trichoderma, Bacillus, and ADMF® were demonstrated to reduce disease incidence and promote banana vegetative growth, proving to be viable sustainable alternatives for this crop. Keywords: Musa AAA, Trichoderma, Bacillus, ADMF®, Ralstonia solanacearum, AUDPC.

The influence of oviposition status on measures of transmission potential in malaria-infected mosquitoes depends on sugar availability

BackgroundLike other oviparous organisms, the gonotrophic cycle of mosquitoes is not complete until they have selected a suitable habitat to oviposit. In addition to the evolutionary constraints associated with selective oviposition behavior, the physiological demands relative to an organism’s oviposition status also influence their nutrient requirement from the environment. Yet, studies that measure transmission potential (vectorial capacity or competence) of mosquito-borne parasites rarely consider whether the rates of parasite replication and development could be influenced by these constraints resulting from whether mosquitoes have completed their gonotrophic cycle.MethodsAnopheles stephensi mosquitoes were infected with Plasmodium berghei, the rodent analog of human malaria, and maintained on 1% or 10% dextrose and either provided oviposition sites (‘oviposited’ herein) to complete their gonotrophic cycle or forced to retain eggs (‘non-oviposited’). Transmission potential in the four groups was measured up to 27 days post-infection as the rates of (i) sporozoite appearance in the salivary glands (‘extrinsic incubation period' or EIP), (ii) vector survival and (iii) sporozoite densities.ResultsIn the two groups of oviposited mosquitoes, rates of sporozoite appearance and densities in the salivary glands were clearly dependent on sugar availability, with shorter EIP and higher sporozoite densities in mosquitoes fed 10% dextrose. In contrast, rates of appearance and densities in the salivary glands were independent of sugar concentrations in non-oviposited mosquitoes, although both measures were slightly lower than in oviposited mosquitoes fed 10% dextrose. Vector survival was higher in non-oviposited mosquitoes.ConclusionsCosts to parasite fitness and vector survival were buffered against changes in nutritional availability from the environment in non-oviposited but not oviposited mosquitoes. Taken together, these results suggest vectorial capacity for malaria parasites may be dependent on nutrient availability and oviposition/gonotrophic status and, as such, argue for more careful consideration of this interaction when estimating transmission potential. More broadly, the complex patterns resulting from physiological (nutrition) and evolutionary (egg-retention) trade-offs described here, combined with the ubiquity of selective oviposition behavior, implies the fitness of vector-borne pathogens could be shaped by selection for these traits, with implications for disease transmission and management. For instance, while reducing availability of oviposition sites and environmental sources of nutrition are key components of integrated vector management strategies, their abundance and distribution are under strong selection pressure from the patterns associated with climate change.Graphical