Primary Reproductives Research Articles

Dynamical and numerical analysis of the hepatitis B virus treatment model through fractal–fractional derivative

Infection with the hepatitis B virus (HBV) is a global health problem and may be controlled via appropriate treatment. We use fractional models to understand infectious diseases because fractional models help us understand treatments' effects on hepatitis B better than integer‐order models. In this article, we introduce a new mathematical model for HBV based on the fractal–fractional derivative with a generalized Mittag–Leffler kernel. Firstly, we discuss the fundamental properties, like the equilibria of the model and the primary reproduction number. Then, we investigate the existence of a unique solution to our model. We use an iterative method to solve the proposed model. Further, we discuss the stability of the model through stability theory. Finally, we offer some graphical illustrations for various values of the parameters.

Sensitivity Analysis of SI1I2RS Model for Dengue Fever Transmission

Dengue fever is a disease caused by dengue virus transmitted through Aedes aegypti mosquitoes. This study discusses the SI1I2RS epidemic model in the spread of dengue fever, assuming that people with this disease can experience severe and mild symptoms. The analysis in this research aims to determine the stability of the equilibrium point, primary reproduction number, parameter sensitivity, and numerical simulation to determine the effect of parameters on the dynamics of the spread of dengue fever. The results of this analysis show two equilibrium points, namely the disease-free equilibrium point, which is locally asymptotically stable when R0 1 and the endemic point, which is locally asymptotically stable when R0 1. Numerical simulations show that the change in the parameter of the average bite of individual mosquitoes in humans has a significant effect on the primary reproductive number where when the moderate acidity of individual mosquitoes in humans is 0.05 and the contact rate of disease transmission from infected mosquitoes to susceptible humans is 0.025, it can suppress the spread of dengue fever. Therefore, individuals must maintain cleanliness and take precautions against the spread of dengue fever.

Inter-clonal competition over queen succession imposes a cost of parthenogenesis on termite colonies.

In social insect colonies, selfish behaviour due to intracolonial conflict among members can result in colony-level costs despite close relatedness. In certain termite species, queens use asexual reproduction for within-colony queen succession but rely on sexual reproduction for worker and alate production, resulting in multiple half-clones of a single primary queen competing for personal reproduction. Our study demonstrates that competition over asexual queen succession among different clone types leads to the overproduction of parthenogenetic offspring, resulting in the production of dysfunctional parthenogenetic alates. By genotyping the queens of 23 field colonies of Reticulitermes speratus, we found that clone variation in the queen population reduces as colonies develop. Field sampling of alates and primary reproductives of incipient colonies showed that overproduced parthenogenetic offspring develop into alates that have significantly smaller body sizes and much lower survivorship than sexually produced alates. Our results indicate that while the production of earlier and more parthenogenetic eggs is advantageous for winning the competition for personal reproduction, it comes at a great cost to the colony. Thus, this study highlights the evolutionary interplay between individual-level and colony-level selection on parthenogenesis by queens.

A new cryptic species of Australian Glyptotermes (Isoptera: Kalotermitidae) discovered by effective use of morphological characteristics of primary reproductives

AbstractClosely related species within termite genera often show extremely similar morphology, where morphological characteristics of soldiers alone or imagos (including alates and primary reproductives) alone are sometimes insufficient to establish new species. However, many original descriptions of termite species are based on soldier characteristics alone, because of the seasonal occurrence of alates and the difficulty in collecting primary reproductives. Importantly, primary reproductives of the family Kalotermitidae (so‐called drywood termites) are relatively easy to collect from field colonies compared with those of the other termite families. Here, we describe a new kalotermitid species, Glyptotermes matsuurai sp. nov., from Australia by effective use of morphological characteristics of primary reproductives. Glyptotermes matsuurai is distinguished from the Australian species G. iridipennis Froggatt, 1896 by the mitochondrial cytochrome c oxidase subunit II gene; however, it is not distinguishable from G. iridipennis based on the external morphology of soldiers. It therefore forms a species complex with G. iridipennis. Although we could collect alates of G. matsuurai from only one of the field‐collected colonies kept in the laboratory, we conducted morphological analyses of imagos from multiple colonies by using primary reproductives collected from field colonies. As a result of our morphological analyses of imagos, we found that G. matsuurai is morphologically distinguishable from all other species of Australian Glyptotermes. Thus, when enough alates are unavailable, morphological characteristics of primary reproductives can be used to facilitate the discovery of undescribed cryptic species at least in the genus Glyptotermes and possibly in other genera within the family Kalotermitidae.

Seaqir Covid -19 Mathematical Modell

This research discusses the mathematical model of Covid-19 disease. The model formed consists of 6 components, namely Susceptible (S), Exposed (E), Asymptotically Infected (A), Quarantined (Q), Symptomatic Infected (S), and Recovered (R). This research aims to determine the local stability analysis of the model formed. Apart from that, the R0 value of the model is also looked for. The model stability analysis was carried out in disease-free and endemic settings by showing asymptotic stability. Based on the analysis results obtained. The primary reproduction number for disease-free and endemic simulations is greater than 1. The interpretation of the COVID-19 mathematical model from the stability analysis shows that COVID-19 will still exist for a specific time and will not disappear.

Transcriptomic profiling of castes and of sexually and parthenogenetically produced reproductive females in the termite Cavitermes tuberosus

AbstractIn termites with a true worker caste, the development pattern splits up from early developmental stages: primary reproductives develop through the nymphal line, whereas workers and soldiers follow the apterous developmental line. In some species, such as Cavitermes tuberosus Emerson (Isoptera: Termitidae, Termitinae), secondary reproductives (or neotenics) may also develop through the nymphal line from a transitional stage called aspirant. Aspirants originate mostly from automictic parthenogenetic reproduction. Therefore, C. tuberosus queens originate from sexual (primary queens) or parthenogenetic (neotenic queens) reproduction. A comparison of these two queen castes offers the possibility to better understand core molecular underpinnings of caste development and plasticity in termites. We investigated these molecular mechanisms by using high‐throughput Illumina RNA sequencing of pooled individuals. We first assembled the de novo reference transcriptome of C. tuberosus, and then identified the transcripts consistently co‐expressed across castes, sexes, and two alternative routes to female reproduction. Cavitermes tuberosus final transcriptome had 130 874 transcripts, N50 of 3398, and total length of 213 549 184 bp. We found that female reproductive maturation was characterized by gene expression down‐regulation: primary queens expressed fewer transcripts overall and had the greatest number of down‐regulated transcripts when compared to all other castes. In both secondary and primary queens, biological processes involved in muscle development and contraction, flight, and olfactory learning were enriched in the down‐regulated gene cluster. In contrast, processes related to reproductive development, insulin receptor signaling pathway, isoprenoid biosynthesis, and multiple metabolic processes were enriched among up‐regulated genes in primary queens. Finally, we found that 17% of all transcripts (21852) were differently co‐expressed when females from sexual and parthenogenetic origins were compared, even though the expression profile of core reproductive‐related gene clusters showed a similar trend in all reproductive females despite their origin. Our findings fit the genomic imprinting model predictions of a maternal effect that commonly regulates the expression of core reproductive genes in females from parthenogenetic and non‐parthenogenetic origins, whereas the expression of non‐reproductive genes varies.

Equivalent Colony Growth of Hybrids of Two Invasive Coptotermes Species Can Threaten Urban Areas.

Coptotermes formosanus Shiraki and C. gestroi (Wasmann) are economically important structural pests in urban areas. Due to anthropogenic activity, both species have been introduced into the United States, with their respective invasive ranges now overlapping in Florida, and the two species have the capability to hybridize. The potential for structural damage from subterranean termite colonies primarily depends on colony size. However, long-term colony growth and wood consumption capabilities of hybrid Coptotermes colonies remain to be investigated, to determine the potential pest status of field-established hybrid colonies. In this study, we investigated long-term colony development over four years to determine if aging hybrid colonies display vigor in terms of colony growth. In addition, we compared wood consumption rate of hybrid colonies to compare their potential impact as structural pests with the two parental species. In aging colonies (four-year-old), both hybrid mating types displayed a colony growth equivalent to C. formosanus. However, the wood consumption rates of four-year-old colonies of the two parental Coptotermes species and their hybrids were similar, indicating equal damaging potential. We also found multiple secondary reproductives in hybrid colonies, even in the presence of primary reproductives, which may favor their potential establishment and spread. Although hybrid colonies or hybrid alates have yet to be detected in the field, our results suggest that such hybrid colonies would be an additional termite threat in the future if they were established in the field.

Succession of the microbiota in the gut of reproductives of Macrotermes subhyalinus (Termitidae) at colony foundation gives insights into symbionts transmission

Termites have co-evolved with a complex gut microbiota consisting mostly of exclusive resident taxa, but key forces sustaining this exclusive partnership are still poorly understood. The potential for primary reproductives to vertically transmit their gut microbiota (mycobiome and bacteriome) to offspring was investigated using colony foundations from field-derived swarming alates of Macrotermes subhyalinus. Metabarcoding based on the fungal internal transcribed spacer (ITS) region and the bacterial 16S rRNA gene was used to characterize the reproductives mycobiome and bacteriome over the colony foundation time. The mycobiome of swarming alates differed from that of workers of Macrotermitinae and changed randomly within and between sampling time points, highlighting no close link with the gut habitat. The fungal ectosymbiont Termitomyces was lost early from the gut of reproductives, confirming the absence of vertical transmission to offspring. Unlike fungi, the bacteriome of alates mirrored that of workers of Macroterminae. Key genera and core OTUs inherited from the mother colony mostly persisted in the gut of reproductive until the emergence of workers, enabling their vertical transmission and explaining why they were found in offspring workers. These findings demonstrate that the parental transmission may greatly contribute to the maintenance of the bacteriome and its co-evolution with termite hosts at short time scales.

The Antennal Sensilla and Expression Patterns of Olfactory Genes in the Lower Termite Reticulitermes aculabialis (Isoptera: Rhinotermitidae).

The insect olfactory system plays pivotal roles in insect survival and reproduction through odor detection. Morphological and physiological adaptations are caste-specific and evolved independently in workers, soldiers, and reproductives in termites. However, it is unclear whether the olfactory system is involved in the division of labor in termite colonies. In the present study, the antennal sensilla of alates, workers, soldiers, nymphs, and larvae of the termite Reticulitermes aculabialis Tsai et Hwang ( Isoptera: Rhinotermitidae) were investigated. Transcriptomes were used to detect olfactory genes, and differential expression levels of olfactory genes were confirmed in various castes by qRT–PCR analysis. Nine types of sensilla were identified on the antennae of R. aculabialis, and soldiers possessed all 9 types. In 89,475 assembled unigenes, we found 16 olfactory genes, including 6 chemosensory protein (CSP) and 10 odorant-binding protein (OBP) genes. These OBP genes included 8 general odorant-binding protein genes (GOBPs) and 2 pheromone-binding protein-related protein (PBP) genes. Five CSP genes were more highly expressed in alates than in workers, soldiers, larvae, and nymphs, and the expression levels of CSP6 were significantly higher in nymphs. Seven GOBP and two PBP genes exhibited significantly higher expression levels in alates, and there were no significant differences in the expression levels of GOBP2 among workers, soldiers, alates, and larvae. These results suggest that alates, as primary reproductives, have unique expression patterns of olfactory genes, which play key roles in nuptial flight, mate seeking, and new colony foundation.

Comparative reproductive biology of pre-, imaginal, and neotenic castes of the Asian termite Coptotermes gestroi (Blattaria, Isoptera, Rhinotermitidae).

The Asian subterranean termite Coptotermes gestroi is a worldwide structural pest, although its reproductive biology has been poorly investigated due to a cryptic habit and occurrence of polycalic nests. In this study, we investigated ovarian development and oogenesis in different-aged females of C. gestroi: fourth-instar nymphs, non-functional neotenics, alates, and functional queens. We show that the ovaries develop gradually according to their age and functionality, as younger individuals possess immature oocytes, whereas alates and functional queens always undergo vitellogenesis. Oocytes were classified into previtellogenic (stages I, II, and III) or vitellogenic (stages IV, V, and VI). Ovary development varied among non-functional neotenics, and a rapid differentiation and/or the presence of primary reproductives are believed to influence such a maturation. Immature oocyte stages were shared between fourth-instar nymphs and neotenics. These characteristics, together with other neotenic features (wing buds, body pigmentation, and eye color), should be evaluated in detail aiming to clarify which nymphal instars differentiate into secondary reproductives. Oogenesis was not uniform among alate females, and cross-sectional area of terminal oocytes was significantly smaller in alates when compared to functional queens, suggesting different degrees of maturation in swarming individuals. Functional queens always had mature terminal oocytes (stage VI). Ovariole number and oocyte maturation in C. gestroi relies on several factors and may therefore differ among individuals of the same caste. Future studies should take into account these reproductive features to evaluate how they impact colony development.

DYNAMIC ANALYSIS OF THE COVID-19 MODEL WITH ISOLATION FACTORS

Covid-19 is a type of infectious disease caused by SARS Cov-2. This virus has spread throughout the world to cause a pandemic. This study aimed to model and analyze the spread of Covid-19 with the isolation factor. The spread of Covid-19 can be made into an epidemic model by taking into account the population of susceptible humans (S), infected humans (I), isolated humans (L), and recovered humans (R). The method used in this research was to derive a non-linear system of differential equations model, complete the model qualitatively, find the primary reproduction ratio ( , see the model’s behavior by analyzing the dynamics of the equilibrium point and make model simulations. This model has a disease-free equilibrium point that is asymptotically stable, while at the equilibrium point, the endemic is unstable. The results of the model simulation and analysis of the value indicate that the chance of successful Covid-19 spread and the isolation factor is a significant controlled parameter in reducing the value.

INSIGHTS OF CASTE DETERMINATIONS IN SOCIAL INSECTS

Eusocial insects display caste structures in which reproductive ability is possessed by a single or a few queens while all other colony members act as workers. In social insects like ants, bees, and termites, vital physiological processes are regulated at the colony scale. Females in social insects have at least one reproductive caste and one nonreproductive caste; many termites have at least two male castes. The castes have considerable anatomical, physiological, and behavioural differences in higher social insects. Organismal systems, such as pheromone sensing, hormone signaling, and brain signaling pathways, are deployed in novel circumstances to impact nestmate and colony behaviours due to physiological decentralization over evolutionary time. Significant morphogenesis with region-specific cellular proliferation and degradation occurs during soldier development through two moulting via a presoldier stage in termite. JH action has been developed, in which a high JH titer causes soldier differentiation and a low JH titer causes alate differentiation. A monogamous pair of primary reproductives (one king and one queen) generated from alates normally establishes termite colonies (winged adults). The nymph-alate pathway (sexual pathway) or the worker pathway differentiates larvae in Reticulitermes termites (neuter pathway). Haplo-diploid sex determination controls the first developmental transition, in which unfertilized (haploid) embryos become males and fertilized (diploid) embryos become females in the case of Cataglyphis ant genus. The queen’s mandibular gland secretion, a mix of fatty acids and aromatic chemicals, is critical for maintaining the reproductive division of labour in honeybees (Apis mellifera), suppressing ovary growth in workers. Besides this, the brood produced by the queen also inhibits ovary development in workers by emitting two pheromones: the brood pheromone (BP), mainly composed of esters, and the highly volatile E-b-ocimene.

Mathematical modeling of bird flu with vaccination and treatment for the poultry farms

A deterministic six-compartmental model was developed based on the progression of the disease in poultry, the epidemiological status of the individuals, and intervention measures. The Runge-Kutta method is applied to calculate the variables of the system of equations of the proposed model. The evolution of the epidemic provides some results, such as reproduction number, vaccine efficiency, and antiviral treatment. Numerical results show that the outbreak sizes known as the infected curves increase and decrease with the vaccine limitation rate and treatment rate, respectively, for a specific transmission rate. The calculated results of the reproduction number indicate that avian influenza would spread when vaccine efficiency is less than 70%, and the primary reproduction number is greater than 1. Finally, the disease-free equilibrium of the model is found locally and globally asymptotically stable for R0 < 1.

Queen Egg Laying and Egg Hatching Abilities are Hindered in Subterranean Termite Colonies When Exposed to a Chitin Synthesis Inhibitor Bait Formulation.

Subterranean termite control methods using chitin synthesis inhibitors (CSIs) aim at eliminating colonies that feed upon a bait formulation. Several benzoylurea active ingredient formulations are currently commercially available as alternative termite management strategies to liquid termiticides. Individual workers need to molt on a regular basis and CSIs interfere with such molting process, allowing sufficient time for the acquisition of a colony-wide lethal dose prior to widespread mortality. As workers progressively die, the colony eventually collapses, leaving only soldiers and primary reproductives that starve to death. One common observation is that young workers often die early owing to their relatively short molting cycle. However, the absence of brood in dying colonies raises questions about the potential fate of eggs laid by the queen. This study aims to determine if CSI baits also terminate the ability of a colony to produce a new cohort of workers by disabling the ongoing brood development. Incipient termite colonies were used to test the impact of noviflumuron on the queen's ability to lay eggs and on the eggs' ability to hatch. Our results showed that queens in colonies exposed to CSI not only initially laid less eggs than the control queens, but eggs also did not develop and were progressively cannibalized, eventually leading to colony establishment failure. This result implies that queens of mature colonies exposed to CSI would lose the ability to lay viable eggs as the colony collapses, leading to an absence of worker replacement, aiding in colony elimination.

Experience-expectant brain plasticity corresponds to caste-specific abiotic challenges in dampwood termites (Zootermopsis angusticollis and Z. nevadensis).

Hypotheses for adaptive brain investment predict associations between the relative sizes of functionally distinct brain regions and the sensory/cognitive demands animals confront. We measured developmental differences in the relative sizes of visual processing brain regions (optic lobes) among dampwood termite castes to test whether optic lobe investment matches caste differences in exposure to visually complex environments. The winged primary reproductives (Kings/Queens) on mating flights are the only caste to leave the dark nest cavities and as predicted, Kings/Queens showed greater relative investment in optic lobe tissue than nestbound (neotenic) reproductives and soldiers in two dampwood termite species (Zootermopsis angusticollis and Z. nevadensis). Relative optic lobe size spanned more than an order of magnitude among the castes we studied, suggesting the growth of the optic lobes incurs substantial tissue costs. Optic lobe growth was experience-expectant: the optic lobes of Z. angusticollis brachypterous nymphs, which typically develop into Kings/Queens, were relatively larger than the optic lobes of apterous nymphs, which precede neotenics and soldiers, and relative optic lobe size of nestbound brachypterous nymphs was statistically similar to that of Kings/Queens. Experience-expectant brain tissue growth is rarely documented in insects, likely because it entails high potential costs of tissue production and maintenance and relatively low immediate sensory/cognitive benefits. We develop hypotheses for the conditions under which experience-expectant growth in brain regions could be favored by natural selection.

Can Non-Pharmaceutical Interventions Contain the Spreading of Novel Coronavirus SARS-CoV-2 in the Asia Pacific Countries?

A novel coronavirus, namely SARS-CoV-2, has emerged rapidly and overspread worldwide, causing a pandemic disease, COVID-19. Until now, no pharmaceutical interventions specific to the COVID-19 infection has been proven effective. In these circumstances, non-pharmaceutical interventions, for example, banning local and international flights, national lockdowns of cities, social distancing, self-isolation, home-quarantine, the closure of schools and universities, closure of government and private offices, banning of mass gatherings would play a vital role in minimizing the primary reproduction number (R0) in expected level. Many Asia Pacific countries, Bangladesh, China, India, Iran, Nepal, New Zealand, Pakistan, and Vietnam, adopt, practice, and implement those non-pharmaceutical interventions and have success stories. Thereby, non-pharmaceutical interventions can contain the virus's spreading, which further reduces long waiting for the healthcare system's hospitalization and burden.

Distinct chemical blends produced by different reproductive castes in the subterranean termite Reticulitermes flavipes

The production of royal pheromones by reproductives (queens and kings) enables social insect colonies to allocate individuals into reproductive and non-reproductive roles. In many termite species, nestmates can develop into neotenics when the primary king or queen dies, which then inhibit the production of additional reproductives. This suggests that primary reproductives and neotenics produce royal pheromones. The cuticular hydrocarbon heneicosane was identified as a royal pheromone in Reticulitermes flavipes neotenics. Here, we investigated the presence of this and other cuticular hydrocarbons in primary reproductives and neotenics of this species, and the ontogeny of their production in primary reproductives. Our results revealed that heneicosane was produced by most neotenics, raising the question of whether reproductive status may trigger its production. Neotenics produced six additional cuticular hydrocarbons absent from workers and nymphs. Remarkably, heneicosane and four of these compounds were absent in primary reproductives, and the other two compounds were present in lower quantities. Neotenics therefore have a distinct ‘royal’ blend from primary reproductives, and potentially over-signal their reproductive status. Our results suggest that primary reproductives and neotenics may face different social pressures. Future studies of these pressures should provide a more complete understanding of the mechanisms underlying social regulation in termites.

Endocuticle is involved in caste differentiation of the lower termite.

Caste differentiation in termites is one of the most conspicuous examples of facultative polyphenism in animals. It is clear that specific cuticular formation occurs in hard exocuticles during caste differentiation. However, the developmental pattern of the soft endocuticle in the differentiation pathways of castes is unknown. To reveal whether the endocuticle is involved in caste differentiation, we compared the exocuticle and endocuticle thickness of individuals in 2 pathways (nymph line and worker line) of caste differentiation in the termite Reticulitermes aculabialis. The endocuticle protein genes were identified by transcriptome analysis and the expression patterns of these genes were confirmed in caste differentiation. We found that the endocuticle structure showed dynamic changes in 2 pathways, and the first difference in endocuticle structure occurred after larvae differentiation bifurcated into workers and nymphs. The thinning of the endocuticle was a significant event from nymphs developing into alates with the thickest exocuticle and thinnest endocuticle. The thickest endocuticle layers were found in the heads of the workers and the ultrastructure of the endocuticle in the heads was more complex than that in the thorax–abdomens. Six endocuticle protein genes were identified and annotated as endocuticle structural glycoproteins SgAbd-2, SgAbd-9, and Abd-5. The expression levels of endocuticle protein genes changed dramatically during caste development and the expression levels in neotenic reproductives (secondary reproductives) were significantly higher than those in alates (primary reproductives). These results reveal the roles of endocuticles in caste differentiation and adaptation to the environment.

Physiological changes of primary reproductives after founding incipient colonies in the subterranean termite Reticulitermes chinensis Snyder

Investigation on the physiological change in founders is helpful for understanding the strategy of termites to overcome severe and nutrition-limited condition in incipient colonies. Physiological changes of primary reproductives were analyzed 0.5, 1.5, 2.5, 3.5 and 7.5 months after founding incipient female-female (FF) colonies or female-male (FM) colonies in the subterranean termite R. chinensis Snyder. We found that the fresh weight of FM_king or FM_queen was significantly lower than those of FF_queen at 7.5 months, suggesting that FM_king and FM_queen underwent dehydration and hardening to improve their cold resistance. There was a significantly negative linear correlation in the protein titer between FF_queen and FM_queen at 3.5 months. The decrease in protein titer of FF_queen may be due to oviposition and eggs-guarding at 1.5 months, and the subsequent increase may be due to swallowing eggs. The increase in protein titer of FM_queen at 1.5 months may be because the king can replenish the queen with protein through the transfer of proctodeal pellets, while the subsequent decrease may be due to sharply increased consumption of protein by incubation and brooding. There was marginally significant negative correlation between glucose and triglyceride titers in FM_queen and FM_king at 3.5 months, respectively. These findings suggested that indirect mutual conversion of glucose and triglyceride may occur without external nutritional supplement in primary reproductives of R. chinensis.

Effect of Population Density on the Model of the Spread of Measles

This study is expected to contribute to the health sector, specifically to describe the dynamics of the measles spread through the models that have been analyzed. One of the factors that became the focus of this study was reviewing the influence of population density on measles spread. The initial step formulated the model and then determined the primary reproduction number and analyzed the stability of the model equilibrium point. The results of the analysis of this model show that there are two conditions for the value of which is a requirement that the existence of two model equilibrium points as well as local stability is needed, namely and . When , there exists a unique equilibrium point, called the non-endemic equilibrium point denoted by . Conversely, when , there are two equilibrium points, namely and the endemic equilibrium point characterized by . The results of local stability analysis show that when , the equilibrium point is stable asymptotic locally. It means that if hold, then in a long time there will not be a spread of disease in the susceptible and vaccinated sub-population, or in other words, the outbreak of the disease will stop. Conversely, when equilibrium point is stable asymptotic locally. It means that if , then measles disease is still in the environment for an infinite time with the condition of the proportions of each sub-population approach to , , and .