PICC Your Poison: Resident Beliefs and Attitudes Regarding Discharge Parenteral Antibiotics for Patients Who Inject Drugs.

Background: Serious injection-related infections (SIRIs) in people who inject drugs often lead to prolonged hospitalizations or premature discharges. This may be in part due to provider reluctance to place peripherally inserted central catheters (PICCs) for outpatient parenteral antibiotic therapy in this population. Because internal medicine (IM) residents are often frontline providers in academic centers, understanding their perspectives on SIRI care is important to improve outcomes. Methods: We surveyed IM residents in a large urban multicenter hospital system about SIRI care with a novel case-based survey that elicited preferences, comfort, experience, and stigma. The survey was developed using expert review, cognitive interviewing, and pilot testing. Results are reported with descriptive statistics and linear regression. Results: Of 116 respondents (response rate 34%), most (73%) were uncomfortable discharging a patient with active substance use home with a PICC, but comfortable (87%) with discharge to postacute facilities. Many (∼40%) endorsed high levels of concern for PICC misuse or secondary line infections, but larger numbers cited concerns about home environment (50%) or loss to follow-up (68%). While overall rates were low, higher stigma was associated with more concerns around PICC use (r = -0.3, P = .002). A majority (58%) believed hospital policies against PICC use in SIRI may act as a barrier to discharge, and 74% felt initiation of medications for opioid use disorder (MOUD) would increase their comfort discharging with a PICC. Conclusions: Most IM residents endorsed high levels of concern about PICC use for SIRI, related to patient outcomes and perceived institutional barriers, but identified MOUD as a mitigating factor.

Reversible colour change in Arthropoda.

The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry.

Is the hibiscus harlequin bug aposematic? The importance of testing multiple predators.

Aposematism involves predators learning conspicuous signals of defended prey. However, prey species utilize a wide range of chemical (or physical) defenses, which are not likely to be equally aversive to all predators. Aposematism may therefore only be effective against a physiologically sensitive subset of potential predators, and this can only be identified through behavioral testing. We studied the emerging model organism Tectocoris diophthalmus (Heteroptera: Scutelleridae), an aposematically colored but weakly defended shieldback stinkbug, to test the efficacy of its defenses against a suite of predator types. We predicted the bugs' defenses would be ineffectual against both experienced and naïve birds but aversive to predaceous insects. Surprisingly, the opposite pattern was found. Both habituated wild passerines and naïve chickens avoided the bugs, the chickens after only one or two encounters. To avian predators, T. diophthalmus is aposematic. However, praying mantids showed no repellency, aversion, or toxicity associated with adult or juvenile bugs after multiple trials. Comparison with prior studies on mantids using bugs with chemically similar but more concentrated defenses underscores the importance of dose in addition to chemical identity in the efficacy of chemical defenses. Our results also emphasize the importance of behavioral testing with multiple ecologically relevant predators to understand selective pressures shaping aposematic signals and chemical defenses.

Mechanisms of color production in a highly variable shield-back stinkbug, Tectocoris diophthalmus [corrected] (Heteroptera: Scutelleridae), and why it matters.

Theory suggests that aposematism, specifically the learned avoidance of unprofitable prey via memorable color patterns, should result in selection for pattern uniformity. However, many examples to the contrary are seen in nature. Conversely, honest sexual signals are likely to exhibit greater variation because they reflect underlying variation in mate quality. Here we aim to characterize and quantify the mechanistic causes of color in Tectocoris diophthalmus [corrected] to shed light on the costs of color production, and thus the potential information content of its color signals. We use Tectocoris diophthalmus [corrected] because it is a weakly-defended stinkbug, and presents elements that have classically been studied in the context of aposematism (red coloring), and sexual selection (sexual dichromatism and iridescent coloring). Pigment analysis reveals that variation in orange coloration is due to the amount of erythropterin pigment, stored in intracellular granules. This pigment is common in Heteroptera, and as an endogenously produced excretory byproduct is unlikely to reflect mate quality or variation in unprofitability of the bug. Electron microscopy reveals the iridescent patches are caused by an epicuticular multilayer reflector, and the hue and patch size are directly related to the layer widths and extent of coverage of this layering. Furthermore, we identified melanin as an essential component of the multilayer reflector system; therefore, the quality of the iridescent patches may be affected by aspects of rearing environment and immunocompetence. We posit that T. diophthalmus [corrected] has co-opted the melanic patches of a 'typical' red and black aposematic signal, transforming it into a complex and variable iridescent signal that may enhance its capacity to display individual quality.