Life-History Traits Of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) And Its Associated Non-Consumptive Effects On Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) Behavior And Development

Blow fly (Diptera: Calliphoridae) interactions in decomposition ecology are well studied; however, the non-consumptive effects (NCE) of predators on the behavior and development of prey species have yet to be examined. The effects of these interactions and the resulting cascades in the ecosystem dynamics are important for species conservation and community structures. The resulting effects can impact the time of colonization (TOC) of remains for use in minimum post-mortem interval (mPMI) estimations. The development of the predacious blow fly, Chrysomya rufifacies (Macquart) was examined and determined to be sensitive to muscle type reared on, and not temperatures exposed to. Development time is important in forensic investigations utilizing entomological evidence to help establish a mPMI. Validation of the laboratory-based development data was done through blind TOC calculations and comparisons with known TOC times to assess errors. A range of errors was observed, depending on the stage of development of the collected flies, for all methods tested with no one method providing the most accurate estimation. The NCE of the predator blow fly on prey blow fly, Cochliomyia macellaria (Fabricius) behavior and development were observed in the laboratory. Gravid female adult attraction was significantly greater to resources with predatory larvae rather than prey larvae and oviposition occurred on in the presence of heterospecific (predatory) and conspecific larvae equally. However, the life stages necessary for predation to occur never overlapped and so these results may not be as surprising as they seem. Conversely, exposing prey larvae to predator cues through larval excretions/secretions led to larger prey larvae and faster times to pupariation when appropriate life stages overlapped. Differences in size and development times of prey larvae in the presence of predatory cues could lead to errors when estimating the mPMI. These data also partially explain the ability of C. macellaria to survive in the presence of Ch. rufifacies. Colonization of a resource with late instar Ch. rufifacies enhanced development and size of resulting larvae indicating that lag colonization, rather than being a primary colonizer, could become an alternate strategy for C. macellaria to survive the selective pressures of the predator, Ch. rufifacies. The differing effects of temperature on Ch. rufifacies and C. macellaria may also lend an advantage to C. macellaria over the predacious Ch. rufifacies in an environment with variable temperatures unlike what Ch. rufifacies is adapted for

A metagenomic assessment of the bacteria associated with Lucilia sericata and Lucilia cuprina (Diptera: Calliphoridae)

Lucilia Robineau-Desvoidy (Diptera: Calliphoridae) is a blow fly genus of forensic, medical, veterinary, and agricultural importance. This genus is also famous because of its beneficial uses in maggot debridement therapy (MDT). Although the genus is of considerable economic importance, our knowledge about microbes associated with these flies and how these bacteria are horizontally and trans-generationally transmitted is limited. In this study, we characterized bacteria associated with different life stages of Lucilia sericata (Meigen) and Lucilia cuprina(Wiedemann) and in the salivary gland of L. sericata by using 16S rDNA 454 pyrosequencing. Bacteria associated with the salivary gland of L. sericata were also characterized using light and transmission electron microscopy (TEM). Results from this study suggest that the majority of bacteria associated with these flies belong to phyla Proteobacteria, Firmicutes, andBacteroidetes, and most bacteria are maintained intragenerationally, with a considerable degree of turnover from generation to generation. In both species, second-generation eggs exhibited the highest bacterial phylum diversity (20 % genetic distance) than other life stages. The Lucilia sister species shared the majority of their classified genera. Of the shared bacterial genera, Providencia, Ignatzschineria, Lactobacillus, Lactococcus, Vagococcus, Morganella, and Myroides were present at relatively high abundances. Lactobacillus, Proteus,Diaphorobacter, and Morganella were the dominant bacterial genera associated with a survey of the salivary gland of L. sericata. TEM analysis showed a sparse distribution of both Gram-positive and Gram-negative bacteria in the salivary gland of L. sericata. There was more evidence for horizontal transmission of bacteria than there was for trans-generational inheritance. Several pathogenic genera were either amplified or reduced by the larval feeding on decomposing liver as a resource. Overall, this study provides information on bacterial communities associated with different life stages of Lucilia and their horizontal and trans-generational transmission, which may help in the development of better vector-borne disease management and MDT methods

Is macroporosity controlled by complexed clay and soil organic carbon?

Multi-scale evidence of rapid, climate-induced soil structural changes occurring at yearly to decadal timescales is mounting. As a result, it has become increasingly important to identify the properties and mechanisms controlling the development and maintenance of soil structure and associated macroporosity. This is especially relevant since macroporosity has disproportionate effects on saturated hydraulic conductivity ( ) which strongly influences water storage and flux, thus, affecting the water cycle. In this study, we use decision trees and piecewise linear regression to assess the influence of soil and climate properties on effective porosity (EP; a proxy of macroporosity) in both surface and subsurface horizons under varying land-use and management practices. Data from 1,491 pedons (3,679 horizons) spanning five ecoregions representing bioclimate (e.g., potential vegetation) across the conterminous US demonstrate that, at a continental scale, EP in surface (A) and subsurface (B) horizons is strongly dependent on the complexed fraction of the total mass of soil organic carbon (SOC) and clay; a combined fraction that we refer to as complexed organic carbon and clay (COCC). EP showed a slight positive response to COCC in A horizons but increased steeply with increasing COCC in B horizons. This is because the smaller values of COCC in B horizons reflect a larger pool of clay that has a greater potential to accommodate and complex additions of SOC promoting stronger organo-mineral bonds and the concomitant development and maintenance of soil structure in these horizons. In contrast, larger values of COCC in A horizons reflect conditions where all or most of the clay fraction is effectively complexed with SOC resulting in a larger pool of non-complexed soil organic matter with varying contrasting effects on macroporosity that ultimately mute the response of EP to increases in COCC. In surface horizons, indirect factors such as mean annual precipitation and land use were important predictors of EP, whereas COCC was more influential in controlling EP within the subsoil. The EP-COCC relationship also holds within ecoregions but its effect is mitigated by soil and climate interactions suggesting that the effect of climate on this relationship is indirect and complex. Plowed surface horizons and horizons underlying plowed layers showed greater homogenization (due to disturbance effects reducing heterogeneity in the soil) as well as a reduction in the magnitude and rate of change of EP as a function of COCC compared to undisturbed horizons. Our findings suggest that the complexed fraction of clay and SOC is important for controlling macroporosity and at ecoregion scales and that the EP-COCC relationship may be an important framework for understanding and predicting future land use- and climate-induced changes in soil hydraulic properties.publishedVersio

FABP7: a glial integrator of sleep, circadian rhythms, plasticity, and metabolic function

Sleep and circadian rhythms are observed broadly throughout animal phyla and influence neural plasticity and cognitive function. However, the few phylogenetically conserved cellular and molecular pathways that are implicated in these processes are largely focused on neuronal cells. Research on these topics has traditionally segregated sleep homeostatic behavior from circadian rest-activity rhythms. Here we posit an alternative perspective, whereby mechanisms underlying the integration of sleep and circadian rhythms that affect behavioral state, plasticity, and cognition reside within glial cells. The brain-type fatty acid binding protein, FABP7, is part of a larger family of lipid chaperone proteins that regulate the subcellular trafficking of fatty acids for a wide range of cellular functions, including gene expression, growth, survival, inflammation, and metabolism. FABP7 is enriched in glial cells of the central nervous system and has been shown to be a clock-controlled gene implicated in sleep/wake regulation and cognitive processing. FABP7 is known to affect gene transcription, cellular outgrowth, and its subcellular localization in the fine perisynaptic astrocytic processes (PAPs) varies based on time-of-day. Future studies determining the effects of FABP7 on behavioral state- and circadian-dependent plasticity and cognitive processes, in addition to functional consequences on cellular and molecular mechanisms related to neural-glial interactions, lipid storage, and blood brain barrier integrity will be important for our knowledge of basic sleep function. Given the comorbidity of sleep disturbance with neurological disorders, these studies will also be important for our understanding of the etiology and pathophysiology of how these diseases affect or are affected by sleep

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Larval Therapy and Larval Excretions/Secretions: A Potential Treatment for Biofilm in Chronic Wounds? A Systematic Review

Chronic wounds present a global healthcare challenge and are increasing in prevalence, with bacterial biofilms being the primary roadblock to healing in most cases. A systematic review of the to-date knowledge on larval therapy’s interaction with chronic-wound biofilm is presented here. The findings detail how larval therapy—the controlled application of necrophagous blowfly larvae—acts on biofilms produced by chronic-wound-relevant bacteria through their principle pharmacological mode of action: the secretion and excretion of biologically active substances into the wound bed. A total of 12 inclusion-criteria-meeting publications were identified following the application of a PRISMA-guided methodology for a systematic review. The findings of these publications were qualitatively analyzed to provide a summary of the prevailing understanding of larval therapy’s effects on bacterial biofilm. A further review assessed the quality of the existing evidence to identify knowledge gaps and suggest ways these may be bridged. In summary, larval therapy has a seemingly unarguable ability to inhibit and degrade bacterial biofilms associated with impaired wound healing. However, further research is needed to clarify and standardize the methodological approach in this area of investigation. Such research may lead to the clinical application of larval therapy or derivative treatments for the management of chronic-wound biofilms and improve patient healing outcomes at a time when alternative therapies are desperately needed

Fuzzy optimization of Fenton\u27s reagent and cationic surfactant for sludge dewatering

Sludge is a by-product of wastewater treatment which has a high-water content. Sludge dewatering is performed to reduce its water content prior to its disposal. Through lowering the water content of the sludge, dry solids (DS) are formed. The objective of the study is to minimize the water content of the sludge and the total operating cost. The efficiency of cetyltrimethylammonium bromide (CTAB), ferrous ion (Fe2+), and hydrogen peroxide (H2O2) in dewatering the sludge are evaluated. Parametric study is performed to understand the relationship of the reagent, operating cost in $/L, and water content of the sludge. The e-constraint is applied to determine the boundary limits of the operating cost and water content for the Pareto frontier identification. Through fuzzy optimization, the study can identify the satisficing solution which simultaneously minimizes water content and cost for Fenton’s reagent and CTAB. The combination of the three reagents is observed to enhance the dewaterability of the sludge. The optimal dosage of ferrous ion, hydrogen peroxide and CTAB is 1.00 mg/g DS, 204.53 mg/g DS, and 162.96 mg/g DS, respectively. Thus, the optimal minimum water content using these reagents is 67.97$/L on a 100 mL sludge and an overall satisfaction level of 40.47 %. Keywords: Sludge dewatering, CTAB, hydrogen peroxide, ferrous ion, e-constraint method, Pareto frontier, fuzzy optimization