Biology subjects

Webb, C. E.

Publications and source records attributed to Webb, C. E..

10 recordsLinked to original sources

bioRxiv2026

Effects of Overripe Banana Processing Techniques on the Chemical Composition and Attractancy to Aedes aegypti and Aedes albopictus

The rising incidence of vector-borne diseases transmitted by mosquitoes has become a significant public health concern. The increasing resistance of mosquitoes to conventional insecticides has prompted the need for alternative control strategies such as Attractive Targeted Sugar Baits (ATSBs). While fruit-based attractants have shown promise, the impact of different production methods on their attractiveness remains underexplored. This study investigates the effect of three production techniques of overripe banana (Musa acuminata) extracts: liquid extraction, syrup concentration, and freeze-drying, on the chemical composition and their attractiveness to Aedes aegypti and Aedes albopictus. Extracts were infused into hydrogel beads and tested in dual-choice olfactometer assays to mosquito vectors Ae. aegypti and Ae. albopictus. Chemical profiling was conducted through Gas chromatography-mass spectrometry (GC-MS) and enzymatic sugar analysis. Results showed that all banana extracts were significantly more attractive than the 10% sucrose control. Among the extracts, syrup concentrates showed the highest attraction (PI = 0.58 {+/-} 0.17 for Ae. aegypti; 0.58 {+/-} 0.14 for Ae. albopictus), followed by freeze-dried (PI = 0.52 {+/-} 0.20; 0.54 {+/-} 0.08) and liquid extracts (PI = -0.40 {+/-} 0.04; 0.49 {+/-} 0.18). GC-MS analysis revealed that freeze-dried powder retained the greatest diversity and abundance of volatile organic compounds (VOCs), especially esters like butyl ethanoate and isoamyl acetate, which are known to influence mosquito behaviour. Although syrup concentration resulted in VOCs degradation, it also generated Maillard reaction products, such as sulphur-containing volatiles, which may enhance olfactory cues. Sugar analysis indicated that both syrup and freeze-dried extracts contained higher levels of sucrose (0.35-0.57 g/100g), glucose (21.20-28.70 g/100g), fructose (14.64-17.89 g/100g), and maltose (9.28-15.56 g/100g), aligning with mosquito preferences. Overall, the findings demonstrate that production techniques significantly influence the chemical composition and attractant potential of overripe banana extracts, offering valuable insights for the development of fruit-based mosquito lures in vector surveillance and control strategies.

molecular biology↗

bioRxiv2025

Selective degradation of platelet BTK by PROTAC NX-5948 provides antithrombotic benefits without affecting haemostasis

Current antithrombotic therapies are effective in reducing thrombotic events but are limited by their associated risk of bleeding. BTK acts as a key signalling switch that drives platelet activation during thrombosis but is largely dispensable for routine haemostasis. It is an important non-redundant signalling mediator downstream of the GPVI and CLEC-2 receptors, plays a key role in thrombosis with minimal involvement in haemostasis, making it an attractive antithrombotic target. While BTK inhibitors effectively reduce thrombosis, their clinical use has been limited due to off-target effects. Protein degraders may overcome this limitation by enabling the ubiquitin proteasomal system to selectively target and degrade BTK. We here assessed the ability of the BTK degraders NX-2127 and NX-5948, currently in clinical trials for B cell pathologies, to target platelet BTK for degradation. NX-2127 and NX-5948 induced concentration-dependent degradation of BTK in washed platelets, platelet-rich plasma and whole blood. NX-5948 showed no hook effect and outperformed NX-2127 in potency, efficacy, and degradation kinetics. TMT proteomic analysis confirmed selective BTK degradation by NX-5948 with no evidence of major off-target effects. BTK degradation impaired CRP-mediated integrin IIb{beta}3 activation, P-selectin expression, platelet aggregation and in vitro thrombosis, with PAR-1 mediated platelet function being left intact. Dosing mice with NX-5948 led to efficacious degradation of platelet BTK and impaired CRP-, but not thrombin-, mediated ex vivo platelet function. In vivo, arterial thrombosis was markedly reduced, without an increase in bleeding time. Together, these results highlight NX-5948 as a potent, selective BTK degrader with antithrombotic potential and minimal haemostatic impact. Key PointsO_LIThe BTK degrader NX-5948 potently and selectively degrades platelet BTK and suppresses thrombus formation without affecting bleeding. C_LIO_LITargeting BTK degradation offers a new antithrombotic strategy that spares haemostasis and may aid patients intolerant to DAPT. C_LI

cell biology↗

bioRxiv2025

Mass-planted large bromeliads in an urban landscape increase the risk for mosquitoes of pest and public health concern

Exotic bromeliads (Bromeliaceae) are increasingly used in Australian urban green spaces for their hardiness and aesthetic appeal. However, the water-holding tanks and axils of these plants provide habitat for mosquitoes, raising public health concerns that must be balanced with ecological objectives of urban greening. This study investigated the abundance and species richness of immature and adult mosquitoes associated with bromeliad plantings in Sydney, Australia. Between October 2023 and April 2024, immature mosquitoes were sampled weekly from large bromeliads at 17 locations, and adults were collected with CO-baited Encephalitic Virus Surveillance traps at six sites of contrasting bromeliad density. Specimens were identified to species level, and associations with climatic variables, bromeliad species, and planting characteristics were analysed using generalised linear mixed models. A total of 2,326 immature mosquitoes (three species) and 6,366 adult mosquitoes (ten species) were collected. Aedes notoscriptus and Culex quinquefasciatus dominated both life stages. Total immature abundance increased by 4% for each additional bromeliad in a patch (IRR 1.04, 95% CI 1.02-1.05), and was highest in Alcantarea imperialis (IRR 1.31, 95% CI 0.97-1.77). Weekly-lagged humidity was positively associated with immature counts (IRR 1.01 per 1% increase, 95% CI 1.00-1.03). Adult abundance was significantly higher at high-density compared to low-density bromeliad sites (IRR 0.37, 95% CI 0.23-0.60). Mass plantings of large, water-holding bromeliads might substantially increase mosquito populations in urban environments, elevating pest and public health risks. This highlights the need for integrated mosquito habitat management in sustainable landscaping design and planning. HighlightsO_LIMass bromeliad plantings could substantially increase urban mosquito populations and public health risks. C_LIO_LISites with high-density bromeliads yielded 170% more adult mosquitoes than low-density sites. C_LIO_LIAedes notoscriptus and Culex quinquefasciatus dominated both immature and adult mosquito collections. C_LIO_LIFindings inform sustainable urban landscaping strategies to reduce the pest and public health risks associated with mosquitoes. C_LI

zoology↗

bioRxiv2025

Impact of Sugar-Based Baits on Midgut Microbiome Composition in Aedes Mosquitoes: Implications for Vector Control

Many severe mosquito-borne diseases are transmitted by the Aedes sp. mosquitoes. Control efforts have been strengthened by the implementation of novel integrated vector management techniques such as alginate hydrogel beads and appealing toxic sugar bait. These techniques help to control mosquitoes by taking advantage of their attraction to sugar. Different types of sugar that mosquitoes ingest during feeding can affect the makeup of microbiome in the midgut. Immune priming and baseline immune activity are maintained by mosquito midgut microbiome. Thus, this study is currently focusing on using microbial communities for vector control measures with a particular emphasis on how they consume various forms of sugar. Both wild and lab strain Ae. aegypti and Ae. albopictus mosquito samples were reared and fed with attractive targeted sugar baits (ATSBs) infused with Chrysanthemum, mango, mix and control solutions. Then, the impact on bacterial communities was assessed by using 16S rRNA gene sequences. According to our findings, the majority of the bacterial species in mango and mix treatments belonged to the Enterobacteriaceae family. A total of 24 various bacterial species were found in Aedes mosquitoes that fed on mango ATSBs. All isolates were members of three phyla from Actinobacteria (4.16%), Firmicutes (54.17%), and Proteobacteria (41.67%). Data reveals that different species, strains and diet affect the midgut bacterial diversity in the mosquitoes. In addition to improving our knowledge concerning the way this bacterium shapes the microbial community, a thorough investigation of the prevalence of the midgut bacterial community is essential for alerting present and future mosquito and disease control initiatives.

molecular biology↗

bioRxiv2024

Within-species variation eclipses between-species differences in Pan consolation

Empathy and its subcomponents are well documented throughout the animal kingdom, indicating the deep evolutionary origins of this socioemotional capacity. A key behavioural marker of empathy is consolation, or unsolicited bystander affiliation directed towards distressed others. Consolation has been observed in our closest living relatives, bonobos (Pan paniscus) and chimpanzees (P. troglodytes). However, systematic comparisons are absent, despite potential for interspecific differences. Bonobos are often considered less aggressive, more emotionally sensitive, and more socially tolerant than chimpanzees--key characteristics purported to drive consolation. Furthermore, social and individual factors also appear to drive intraspecific variation in empathy. To address within- and between-species variability in Pan consolation, we systematically tested the consolatory tendencies of large sanctuary-living groups of both species. Bonobos and chimpanzees exhibited similar consolation tendencies; however, within-species analyses revealed further similarities and variation. Bonobo consolation was most often directed towards and received by younger individuals, while chimpanzee consolation was most often directed towards close social partners. In addition, males and females of both species showed decreased consolation with age, with some evidence for chimpanzee males consoling more than young females. Our findings support the notion that within-species variation in Pan socio-emotional abilities is greater than between-species differences, highlighting the presence of striking behavioural diversity across our two closest cousins.

animal behavior and cognition↗

bioRxiv2023

Mapping the landscape pool of ardeid species to landscape structure associated with Japanese encephalitis virus in Australia

Japanese encephalitis virus (JEV), a zoonotic, mosquito-borne virus, has broad circulation across the Central Indo-Pacific biogeographical region (CIPBR), which recently expanded dramatically within this region across southeastern Australia over the summer of 2021-2022. Preliminary investigation of the landscape epidemiology of the outbreaks of JEV in Australian piggeries found associations with particular landscape structure as well as ardeid species richness. The ways in which waterbird species from diverse taxonomic pools with substantial functional variation might couple with JEV-associated landscape structure was not explored, and therefore, key questions regarding the landscape epidemiology and infection ecology of JEV remain unanswered. Moreover, given the established presence of JEV within the CIBPR, the extent to which waterbird species pools in JEV-associated landscapes in Australia reflect broader regional patterns in functional biogeography presents a further knowledge gap particularly with respect to potential virus dispersal via maintenance hosts. The current study investigated waterbird species presence, ecological traits, and functional diversity distribution at landscape scale, and how these aligned with confirmed JEV detections in eastern Australia and the wider CIPBR. The results showed that waterbird habitat associated with JEV detection in Australia in 2022 and more widely across the CIPBR over the last 20 years reflects a range of species representing 8 families in 4 orders (ardeids, anatids, rallids, phalacrocoracids, threskiornithids, gruids, and pelecanids). Increasing waterbird functional diversity (trait-based mean pairwise dissimilarity) was associated with landscapes delineating JEV occurrence, while only one individual trait, high hand-wing index, was consistently associated with species presence in these JEV-associated landscapes in both Australia and the broader CIPBR. This suggests that dispersal capacity among the waterbird species pools that dominate JEV-associated landscapes might be important. By taking an agnostic approach to JEV maintenance host status, this study indicates a relatively large, CIPBR-wide pool of waterbird families associated with JEV landscapes, challenging the narrow view that JEV maintenance is limited to ardeid birds. In addition, these findings highlight the potential for leveraging functional biogeography in high-risk landscapes across broad geographic extent to guide landscape-specific selection of species for JEV surveillance.

ecology↗

bioRxiv2022

Little pig, little pig, let me come in: The influence of landscape structure and La Nina climatic anomalies on the emergence of Japanese encephalitis virus in Australian piggeries in 2022

The widespread activity of Japanese encephalitis virus (JEV) in previously unaffected regions of eastern and southern Australia in 2022 represents the most significant local arbovirus emergency in almost 50 years. Japanese encephalitis virus is transmitted by mosquitoes and maintained in wild ardeid birds and amplified in pigs, the latter of which suffer significant reproductive losses as a result of infection. The landscape of JEV outbreak risk in mainland Australia is almost entirely unknown, particularly in the eastern and southern parts of the country where the virus has not been previously documented. Although other areas with endemic JEV circulation in the Indo-Pacific region have demonstrated the importance of wild waterbird-livestock interface in agricultural-wetland mosaics, no such investigation has yet determined the configuration of pathogenic landscapes for Australia. Moreover, the recent emergence in Australia has followed substantial precipitation and temperature anomalies associated with the La Nina phase of the El Nino Southern Oscillation. This study investigated the landscape epidemiology of JEV outbreaks in Australian piggeries recorded between January and April of 2022 to determine the influence of ardeid habitat suitability, hydrogeography, hydrology, land cover and La Nina-associated climate anomalies in demarcating risk. Outbreaks of JEV in domestic pigs were associated with ardeid species richness, agricultural and riparian landscape mosaics, hydrological flow accumulation, and grasslands. This study has identified the composition and configuration of landscape features that delineated risk for piggeries during the 2022 emergence of JEV in Australia. Although preliminary, these findings can inform actionable strategies for the development of new One Health JEV surveillance specific to the needs of Australia.

ecology↗

bioRxiv2021

Variability in mosquito community composition associated with estuarine wetlands in Northern NSW, Australia

The Northern Rivers region of NSW, Australia, is well documented as being impacted by nuisance-biting mosquitoes and mosquito-borne disease. Mosquitoes of greatest concern are those associated with estuarine and brackish water habitats associated with coastal wetlands and understanding the spatial variability in abundance and diversity will assist the assessment of risk and inform surveillance and control programs. Adult mosquito populations were sampled, using carbon dioxide baited traps, at four locations within the Richmond River estuary at Ballina, NSW, Australia, during January and February 2021. Concomitant sampling of habitats for immature mosquitoes was also undertaken. A total of 16,467 mosquitoes was collected at all sites across two sampling periods with the most abundant mosquitoes, Verrallina funerea, Aedes vigilax, and Culex sitiens, those typically associated with estuarine environments. Culex annulirostris, a mosquito associated with freshwater habitats, and Aedes notoscriptus, a mosquito associated with water-holding containers, were also commonly collected. The mosquito communities differed, in relative abundance and species richness, between the four locations. The result highlighted the need for authorities to understand the variability in productivity of potential mosquito habitats, beyond those determinants associated with vegetation communities alone, when assessing suitable locations of mosquito surveillance and integrated mosquito management.

ecology↗

bioRxiv2020

Age-related degradation of optic radiation white matter connectivity differentially predicts visual and non-visual executive functions

Healthy aging is accompanied by degraded white matter connectivity, which has been suggested to contribute to cognitive dysfunction observed in aging, especially in relation to fluid measures of cognition. Prior research linking white matter microstructure and cognition, however, has largely been limited to major association and heteromodal white matter tracts. The optic radiations (OR), which transfer visual sensory-perceptual information from thalamic lateral geniculate nucleus to primary visual cortex, are generally considered lower-level input-relay white matter tracts. However, the role of this prominent white-matter visual relay system in supporting higher-order cognition is understudied, especially in regard to healthy aging. The present study used deterministic tractography to isolate OR fractional anisotropy (FA) in 130 participants aged 20-94 to assess age effects on OR tract white matter. We also examined associations between age-related differences in the OR and cognitive domains involving visual processing speed, and visual- and non-visual executive function (EF). OR microstructure, as indexed by FA, exhibited a significant linear decrease across age. A significant interaction between age, FA, and cognitive domain on cognitive task performance indicated that in older age, more degraded OR white matter was associated with poorer visual EF, but no age-related association between FA in the OR and visual processing speed or verbal EF was observed. These findings suggest the optic radiations are not merely sensory-perceptual relays, but also influence higher-order visual cognition differentially with age.

neuroscience↗

bioRxiv2019

Contributions of white matter connectivity and BOLD modulation to cognitive aging: A lifespan structure-function association study

The ability to flexibly modulate brain activation to increasing cognitive challenge decreases with aging. This age-related decrease in dynamic range of function of regional gray matter may be, in part, due to age-related degradation of regional white matter tracts. Here, a lifespan sample of 171 healthy adults (aged 20-94) underwent MRI scanning including diffusion-weighted imaging (for tractography) and functional imaging (a digit n-back task). We utilized structural equation modeling to test the hypothesis that age-related decrements in white matter microstructure are associated with altered BOLD modulation, and both in turn, are associated with scanner-task accuracy and executive function performance. Specified structural equation model evidenced good fit, demonstrating that increased age negatively affects n-back task accuracy and executive function performance in part due to both degraded white matter tract microstructure and reduced task-difficulty related BOLD modulation. We further demonstrated that poorer white matter microstructure integrity was associated with weakened BOLD modulation, particularly in regions showing positive modulation effects, as opposed to negative modulation effects. This structure-function association study provides further evidence that structural connectivity influences functional activation, and the two mechanisms in tandem are predictive of cognitive performance, both during the task, and for cognition measured outside the scanner environment.

neuroscience↗