Life Sciences Commons^™

Local Environmental Variables Are Key Drivers Of Ant Taxonomic And Functional Beta-Diversity In A Mediterranean Dryland, Clara Frasconi Wendt, Ana Ceia-Hasse, Alice Nunes, Robin Verble, Giacomo Santini, Mário Boieiro, Cristina Branquinho

Biological Sciences Faculty Research & Creative Works

The decomposition of beta-diversity (β-diversity) into its replacement (β_repl) and richness (β_rich) components in combination with a taxonomic and functional approach, may help to identify processes driving community composition along environmental gradients. We aimed to understand which abiotic and spatial variables influence ant β-diversity and identify which processes may drive ant β-diversity patterns in Mediterranean drylands by measuring the percentage of variation in ant taxonomic and functional β-diversity explained by local environmental, regional climatic and spatial variables. We found that taxonomic and functional replacement (β_repl) primarily drove patterns in overall β-diversity (β_tot). …

Reproductive Aging In Caenorhabditis Elegans: From Molecules To Ecology, Andrea Scharf, Franziska Pohl, Brian M. Egan, Zuzana Kocsisova, Kerry Kornfeld

Biological Sciences Faculty Research & Creative Works

Aging animals display a broad range of progressive degenerative changes, and one of the most fascinating is the decline of female reproductive function. In the model organism Caenorhabditis elegans, hermaphrodites reach a peak of progeny production on day 2 of adulthood and then display a rapid decline; progeny production typically ends by day 8 of adulthood. Since animals typically survive until day 15 of adulthood, there is a substantial post reproductive lifespan. Here we review the molecular and cellular changes that occur during reproductive aging, including reductions in stem cell number and activity, slowing meiotic progression, diminished Notch signaling, and …

Blood Biomarkers For Mild Traumatic Brain Injury: A Selective Review Of Unresolved Issues, Daniel B. Hier, Tayo Obafemi-Ajayi, Matthew S. Thimgan, Gayla R. Olbricht, Sima Azizi, Blaine Allen, Bassam A. Hadi, Donald C. Wunsch

Biological Sciences Faculty Research & Creative Works

Background: The use of blood biomarkers after mild traumatic brain injury (mTBI) has been widely studied. We have identified eight unresolved issues related to the use of five commonly investigated blood biomarkers: neurofilament light chain, ubiquitin carboxy-terminal hydrolase-L1, tau, S100B, and glial acidic fibrillary protein. We conducted a focused literature review of unresolved issues in three areas: mode of entry into and exit from the blood, kinetics of blood biomarkers in the blood, and predictive capacity of the blood biomarkers after mTBI.

Findings: Although a disruption of the blood brain barrier has been demonstrated in mild and severe traumatic brain …

Aridity-Driven Shift In Biodiversity-Soil Multifunctionality Relationships, Weigang Hu, Jinzhi Ran, Longwei Dong, Qiajun Du, Mingfei Ji, Shuran Yao, Chen Hou, For Full List Of Authors, Download The Pdf.

Biological Sciences Faculty Research & Creative Works

Relationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships …

Neonicotinoids Can Cause Arrested Pupal Ecdysis In Lepidoptera, Niranjana Krishnan, Russell A. Jurenka, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Recently, we reported a novel mode of action in monarch butterfly (Danaus plexippus) larvae exposed to neonicotinoid insecticides: arrest in pupal ecdysis following successful larval ecdysis. In this paper, we explore arrested pupal ecdysis in greater detail and propose adverse outcome pathways to explain how neonicotinoids cause this effect. Using imidacloprid as a model compound, we determined that final-instar monarchs, corn earworms (Helicoverpa zea), and wax moths (Galleria mellonella) showed high susceptibility to arrested pupal ecdysis while painted ladies (Vanessa cardui) and red admirals (Vanessa atalanta) showed low susceptibility. Fall …

Evaluating Toxicity Of Varroa Mite (Varroa Destructor)-Active Dsrna To Monarch Butterfly (Danaus Plexippus) Larvae, Niranjana Krishnan, Maura J. Hall, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Varroa mites (Varroa destructor) are parasitic mites that, combined with other factors, are contributing to high levels of honey bee (Apis mellifera) colony losses. A Varroa-active dsRNA was recently developed to control Varroa mites within honey bee brood cells. This dsRNA has 372 base pairs that are homologous to a sequence region within the Varroa mite calmodulin gene (cam). The Varroa-active dsRNA also shares a 21-base pair match with monarch butterfly (Danaus plexippus) calmodulin mRNA, raising the possibility of non-target effects if there is environmental exposure. We chronically exposed the entire monarch …

Monarch Butterfly (Danaus Plexippus) Life-Stage Risks From Foliar And Seed-Treatment Insecticides, Niranjana Krishnan, Yang Zhang, Melanie E. Aust, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Conservation of North America's eastern monarch butterfly (Danaus plexippus) population would require establishment of milkweed (Asclepias spp.) and nectar plants in the agricultural landscapes of the north central United States. A variety of seed-treatment and foliar insecticides are used to manage early- and late-season pests in these landscapes. Thus, there is a need to assess risks of these insecticides to monarch butterfly life stages to inform habitat conservation practices. Chronic and acute dietary toxicity studies were undertaken with larvae and adults, and acute topical bioassays were conducted with eggs, pupae, and adults using 6 representative insecticides: beta-cyfluthrin …

Tuning Polymorphs And Morphology Of Microbially Induced Calcium Carbonate: Controlling Factors And Underlying Mechanisms, Maryam Khanjani, David J. Westenberg, Aditya Kumar, Hongyan Ma

Biological Sciences Faculty Research & Creative Works

Microbially precipitated calcium carbonate (CaCO₃) has drawn broad attention due to its potential applications in various areas, for example, biocementation, medicine, and soil reinforcement. Sporosarcina pasteurii (S. pasteurii), formerly known as Bacillus pasteurii, has been investigated for CaCO₃ biomineralization due to its high ureolytic activity. A high degree of supersaturation with respect to the presence of bacterial cell wall, extracellular polymeric substances, and organic byproducts of bacterial activity plays an important role in the formation and stabilization of CaCO₃ polymorphs. Although microbially induced CaCO₃ and its polymorphs have been investigated broadly, the …

Conservation Risks And Benefits Of Establishing Monarch Butterfly (Danaus Plexippus) Breeding Habitats Close To Maize And Soybean Fields In The North Central United States: A Landscape-Scale Analysis Of The Impact Of Foliar Insecticide On Nonmigratory Monarch Butterfly Populations, Tyler J. Grant, Niranjana Krishnan, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Establishing habitat in agricultural landscapes of the north central United States is critical to reversing the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Insecticide use could create population sinks and threaten recovery. Discouraging habitat establishment within a 38-m zone around crop fields is a suggested risk mitigation measure. In Story County, Iowa, United States, this mitigation would discourage habitat establishment in 84% of roadsides and 38% of noncrop land. It is unclear if the conservation benefits from establishing habitat close to crop fields outweigh suppression of population growth owing to insecticide exposure. Consequently, monarch conservation …

A Food Microbiology Classroom Activity To Draw Connections Between Microbes And Students’ Lives, David J. Westenberg, Jonathan Kopel

Biological Sciences Faculty Research & Creative Works

Fermented foods have been prepared for millennia and every society around the world has traditional fermented foods and/or beverages that are identified with that culture. This is an excellent opportunity to help students draw connections between their everyday lives and the microbial sciences. At the same time, this is also a great way to encourage cultural awareness and acceptance. This manuscript describes an active learning approach used in a general microbiology course to encourage students to learn about fermented foods from around the world and share their discoveries with their colleagues. As a group we also spend time discussing some …

A Population Dynamics Tipping Point For Aging As A Cause Of Adult Death, Andrea Scharf

Biological Sciences Faculty Research & Creative Works

Populations are a fundamental level of biological organization that poses major challenges for analysis. Individual traits that influence development, diapause, reproduction, aging, and lifespan interact in complex ways to determine birth and death. Birth and death drive population dynamics and determine whether a population survives or is doomed for extinction. However, we lack a deep understanding of the relationships between individual traits and population dynamics, a major challenge in the emerging field of ecology-development (eco-devo). Here we establish a laboratory ecosystem using the model organism C. elegans and a computational simulation that realistically models the laboratory ecosystem. We used these …