Nanoconfinements are utilized to program how polymers entangle and disentangle as chain clusters to engineer pseudo bonds with tunable strength, multivalency, and directionality. When amorphous polymers are grafted to nanoparticles that are one magnitude larger in size than individual polymers, programming grafted chain conformations can "synthesize" high-performance nanocomposites with moduli of ≈25GPa and a circular lifecycle without forming and/or breaking chemical bonds. These nanocomposites dissipate external stresses by disentangling and stretching grafted polymers up to ≈98% of their contour length, analogous to that of folded proteins; use both polymers and nanoparticles for load bearing; and exhibit a non-linear dependence on composition throughout the microscopic, nanoscopic, and single-particle levels.
View Article and Find Full Text PDFCollective behaviors of social insects are often regulated by pheromones. In subterranean termites, some workers forage for and exploit decaying wood for new food resources while forming tunnels from their nest. Colonizing new food resources requires workers to build and disinfect tunnels and chambers inside the nest and ingest decaying wood; therefore subterranean termite colonies should have mechanisms to establish and maintain groups of workers to perform these functions.
View Article and Find Full Text PDFWe detail our approach and experience with a hybrid version of the endopelvic hood-sparing (HS) robot-assisted radical prostatectomy (RARP) using the da Vinci robotic platform. We retrospectively reviewed the records of 200 patients who underwent RARP by a single surgeon. Patients were propensity-matched into three cohorts depending on biopsy and prostatectomy Gleason Grade Groups: traditional retropubic (RP) ( = 80), retzius-sparing (RS) ( = 40), and HS ( = 80).
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFThe origin of the German cockroach, , is enigmatic, in part because it is ubiquitous worldwide in human-built structures but absent from any natural habitats. The first historical records of this species are from ca. 250 years ago (ya) from central Europe (hence its name).
View Article and Find Full Text PDFComposite materials comprising polymers and inorganic nanoparticles (NPs) are promising for energy storage applications, though challenges in controlling NP dispersion often result in performance bottlenecks. Realizing nanocomposites with controlled NP locations and distributions within polymer microdomains is highly desirable for improving energy storage capabilities but is a persistent challenge, impeding the in-depth understanding of the structure-performance relationship. In this study, a facile entropy-driven self-assembly approach is employed to fabricate block copolymer-based supramolecular nanocomposite films with highly ordered lamellar structures, which are then used in electrostatic film capacitors.
View Article and Find Full Text PDFNanomaterials must be systematically designed to be technologically viable. Driven by optimizing intermolecular interactions, current designs are too rigid to plug in new chemical functionalities and cannot mitigate condition differences during integration. Despite extensive optimization of building blocks and treatments, accessing nanostructures with the required feature sizes and chemistries is difficult.
View Article and Find Full Text PDFMost population genetic studies concern spatial genetic differentiation, but far fewer aim at analyzing the temporal genetic changes that occur within populations. Vector species, including mosquitoes and biting midges, are often characterized by oscillating adult population densities, which may affect their dispersal, selection, and genetic diversity over time. Here, we used a population of Culicoides sonorensis from a single site in California to investigate short-term (intra-annual) and long-term (inter-annual) temporal variation in genetic diversity over a 3 yr period.
View Article and Find Full Text PDFThe tawny crazy ant, (Mayr) (Hymenoptera: Formicidae) has a native range that extends from northern Argentina to southern Brazil. In the U.S.
View Article and Find Full Text PDFArthropod Struct Dev
November 2022
In termites, the maturation of the female reproductive system is progressive following post-embryonic development. In Silvestritermes euamignathus, the imaginal line is characterized by five nymphal instars that develop into the imago, but it can deviate in some instars to neotenic reproductives. In order to understand the rate of development of the female reproductive system throughout post-embryonic development, we analyzed the morphology of the reproductive system of nymphs, characterizing the stage of development and comparing it with neotenics and primary queens.
View Article and Find Full Text PDFBlends of nanoparticles, polymers, and small molecules can self-assemble into optical, magnetic, and electronic devices with structure-dependent properties. However, the relationship between a multicomponent nanocomposite's formulation and its assembled structure is complex and cannot be predicted by theory. The blends can be strongly influenced by processing conditions, which can introduce non-equilibrium states.
View Article and Find Full Text PDFPopulations of monogyne and polygyne red imported fire ants (RIFA), Buren, are distributed throughout the southern United States. This ant species is hazardous to farm animals and workers, damages infrastructure, and depletes native arthropod populations. Colony expansion is affected by several biotic factors, but the effects of soil microbes on ant behavior related to soil excavation within nest sites have not been investigated.
View Article and Find Full Text PDFExtensive prior work has shown that colloidal inorganic nanocrystals coated with organic ligand shells can behave as artificial atoms and, as such, form superlattices with different crystal structures and packing densities. Although ordered superlattices present a high degree of long-range positional order, the relative crystallographic orientation of the inorganic nanocrystals with respect to each other tends to be random. Recent works have shown that superlattices can achieve orientational alignment through combinations of nanocrystal faceting and ligand modification, as well as selective metal particle attachment to particular facets.
View Article and Find Full Text PDFSocial life and lifelong partner commitments are expected to favor thorough partner choice, as an ill-suited partnership may have long-term consequences, adversely affecting the parents and spanning several cohorts of offspring. Here, we used ~1400 termite incipient colonies to estimate the short- and long-term costs of inbreeding upon the survival of the parents over a 15-month period, their productivity, and the resistance of their offspring toward pathogen pressure. We observed that foundation success was not influenced by the relatedness of partners, but by their levels of microbial load.
View Article and Find Full Text PDFRNA interference (RNAi) selectively targets genes and silences their expression in vivo, causing developmental defects, mortality and altered behavior. Consequently, RNAi has emerged as a promising research area for insect pest management. However, it is not yet a viable alternative over conventional pesticides despite several theoretical advantages in safety and specificity.
View Article and Find Full Text PDFBackground: Proper vector surveillance relies on the ability to identify species of interest accurately and efficiently, though this can be difficult in groups containing cryptic species. Culicoides Latreille is a genus of small biting flies responsible for the transmission of numerous pathogens to a multitude of vertebrates. Regarding pathogen transmission, the C.
View Article and Find Full Text PDFBackground: A frequent goal of pest management strategies targeting social insects is total colony elimination. Insecticidal baits are highly effective at controlling social insect pests, although their ability to provide total colony elimination has only been well studied in a few species. Genetically testing colony elimination in many urban pest ants can be challenging due to indistinct colony boundaries observed in unicolonial, invasive species; however, some pest ants, such as the dark rover ant (Brachymyrmex patagonicus), maintain strict colony borders through aggression towards non-nestmates.
View Article and Find Full Text PDFRNA interference is a powerful tool that post-transcriptionally silences target genes. However, silencing efficacy varies greatly among different insect species. Recently, we attempted to knock down some housekeeping genes in the tawny crazy ant (), a relatively new invasive species in the southern United States, but only achieved relatively low silencing efficiency when dsRNA was orally administered.
View Article and Find Full Text PDFThe inability to distinguish between species can be a serious problem in groups responsible for pathogen transmission. Culicoides biting midges transmit many pathogenic agents infecting wildlife and livestock. In North America, the C.
View Article and Find Full Text PDFEvaluating the factors that promote invasive ant abundance is critical to assess their ecological impact and inform their management. Many invasive ant species show reduced nestmate recognition and an absence of boundaries between unrelated nests, which allow populations to achieve greater densities due to reduced intraspecific competition. We examined nestmate discrimination and colony boundaries in introduced populations of the red imported fire ant (Solenopsis invicta; hereafter, fire ant).
View Article and Find Full Text PDFMaterials capable of degradation upon exposure to light hold promise in a diverse range of applications including biomedical devices and smart coatings. Despite the rapid access to macromolecules with diverse compositions and architectures enabled by ring-opening metathesis polymerization (ROMP), a general strategy to introduce facile photodegradability into these polymers is lacking. Here, we report copolymers synthesized via ROMP that can be degraded by cleaving the backbone in both solution and solid states under irradiation with a 52 W, 390 nm Kessil LED to generate heterotelechelic low-molecular-weight fragments.
View Article and Find Full Text PDFAnnu Rev Entomol
January 2022
Human activity has facilitated the introduction of many exotic species via global trade. Asia-Pacific countries comprise one of the most economically and trade-active regions in the world, which makes it an area that is highly vulnerable to invasive species, including ants. There are currently over 60 exotic ant species in the Asia-Pacific, with the red imported fire ant, , among the most destructive.
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