Ornamental nestling mouth coloration and parental care in house sparrows

Dependent offspring across taxonomically-diverse lineages use behavioral, vocal, chemical, and morphological traits to attract parental care. Such offspring solicitations are often hypothesized to evolve as a means of offspring-parent communication, where offspring traits furnish information about aspects of offspring phenotype of potential interest to parents (e.g., hunger, body size, immune status), and parents use these offspring traits to make adaptive decisions about the level and/or division of investment they provide. While offspring solicitations are widely interpreted as indicative of offspring "need" (more formally, the contribution that a unit of parental investment will make to an offspring's personal fitness), this interpretation seems at odds with the observation that dependent offspring solicit parental care with traits that, when found in adult animals, are typically interpreted as signals of high quality. For example, while soliciting food from provisioning parents, altricial nestling birds commonly reveal elaborately colored mouth parts, including colorful rictal flanges that border the gape. Several lines of evidence suggest that the mouth coloration of nestling birds may be a trait reflecting selective pressures imposed by reliance upon parental care. For example, flanges are present only during the nestling period, and their coloration is restricted to the portion of tissue revealed to parents during begging. I addressed the possibility that the yellow flange coloration of nestling house sparrows may serve in offspring-parent communication by examining i) the potential information content of this trait and ii) parental response to variation. I measured tissue color using reflectance spectrometry and, most often, quantified three features of flange reflectance: i) overall brightness (total reflected light), ii) relative intensity of ultraviolet reflectance (UV peak / an estimate of pigment-free reflectance), and iii) chroma, an estimate of the saturation of yellow coloration. With biochemical extractions, I demonstrated that the yellow flange coloration of nestling house sparrows is carotenoid-based, and that chroma positively reflects the amount of carotenoids present. While the maximum brightness and UV intensity of flange coloration is likely structural in origin, carotenoids limit the expression of these traits through their absorptive properties (i.e., all else being equal, carotenoid-richness is negatively associated with brightness and UV intensity). To account for this effect, I typically analyzed structural features of color with chroma included as a covariate. At days three and six post-hatching, both the carotenoid-richness and brightness (controlling for the effects of carotenoids) of flange tissue have the potential to provide parents with information about their offspring. These features of reflectance were positively associated with nestling mass, tarsus length and circulating carotenoid levels. Carotenoid-richness increased with nestling age, although brightness did not change significantly. Between days three and six post-hatching, the magnitude of ontogenetic changes in both color parameters was positively associated with the amount of mass gained by nestlings, suggesting that food intake influences the development of coloration. There was little evidence that UV coloration contained information about individual phenotype. Even after these individual-level associations among colors and other aspects of nestling phenotype were accounted for statistically (i.e., are included as covariates in models), broods were different from each other. A cross-fostering study revealed that most among-brood variation was explained by factors shared by parents breeding contemporaneously (presumably reflecting environmental variation or similarities among parents themselves); this result was consistent with seasonal differences in color revealed by the descriptive study. Carotenoid-based coloration was influenced by both pre- and post-hatching parental effects, while structural colors (brightness and UV) were not. These parental effects on chick coloration most likely result from differences in carotenoid supply (via yolk or solid food) or physiological consumption (e.g., via immune responses), although genetic differences among parents (captured by nest-of-origin effects) are also possible. In summary, within-brood variation seems likely to capture within-brood status, while among-brood variation likely reflects aspects of the conditions in which broods are reared rather than intrinsic qualities of the brood members themselves. When parents were presented with similarly-sized nestlings with mouth colors manipulated to appear carotenoid-rich or carotenoid-poor, they allocated more resources to the nestlings that appeared carotenoid-rich; this effect was significant only for females, although the trend was similar for males, and the non-significant effect likely reflected low statistical power. These preferences themselves did not indicate that parents were responding to color, in the ultimate sense, because of their information content. If carotenoid-rich colors are more visually conspicuous, parental responses might simply reflect limitations of their sensory systems. To distinguish between these alternatives, I used a model of house sparrow vision to estimate the conspicuousness of flanges under a suite of realistic ambient light conditions, and compared carotenoid-richness (chroma) to conspicuousness (contrast between the flange and interior of the mouth and the flange and nesting material). The achromatic contrast, probably the primary mediator of detectability, was either unaffected by chroma or negatively associated with this proxy for carotenoid richness, depending on ambient light conditions. Overall, these results suggest that carotenoid-based flange coloration plays a functional role in mediating the allocation of parental care, that within-brood parental preferences favor offspring of relatively high value, and that these parental preferences probably (proximately and/or in evolutionary time) exploit the information content of offspring traits to make adaptive life-history decisions. More broadly, these suggest that offspring solicitations may evolve under pressure to signal an individual's status as a promising target for future investment

A Low-Voltage, Ultra-Compact Plasma Spectrometer for Small Spacecraft

Taking advantage of technological developments in wafer-scale processing over the past two decades, such as deep etching, 3-D chip stacking, and double-sided lithography, we have designed, fabricated, and tested the key elements of an ultracompact (1.7cm-x 1.4cm x 1.4cm) plasma spectrometer that requires only low-voltage power supplies, has no microchannel plates, and has a high aperture area to instrument volume ratio. The energy analyzer and collimator components of the instrument are integrated into a single lithographically fabricated layer to optimize alignment of the collimator and eliminate flux reduction penalties typically associated with collimators. We will present tests of the instrument that demonstrate energy analysis of 5 keV electrons with only 5.3 volts of bias and collimator defined angular resolutions that match the design goals of the instrument

Carotenoid Supplementation Enhances Reproductive Success in Captive Strawberry Poison Frogs (Oophaga Pumilio)

Amphibians are currently experiencing the most severe declines in biodiversity of any vertebrate, and their requirements for successful reproduction are poorly understood. Here, we show that supplementing the diet of prey items (fruit flies) with carotenoids has strong positive effects on the reproduction of captive strawberry poison frogs (Oophaga pumilio), substantially increasing the number of metamorphs produced by pairs. This improved reproduction most likely arose via increases in the quality of both the fertilized eggs from which tadpoles develop and trophic eggs that are fed to tadpoles by mothers. Frogs in this colony had previously been diagnosed with a Vitamin A deficiency, and this supplementation may have resolved this issue. These results support growing evidence of the importance of carotenoids in vertebrate reproduction and highlight the nuanced ways in which nutrition constrains captive populations. Zoo Biol. XX:XX-XX, 2013

Model combustion-generated particulate matter containing persistent free radicals redox cycle to produce reactive oxygen species

Particulate matter (PM) is emitted during thermal decomposition of waste. During this process, aromatic compounds chemisorb to the surface of metal-oxide-containing PM, forming a surface-stabilized environmentally persistent free radical (EPFR). We hypothesized that EPFR-containing PM redox cycle to produce ROS and that this redox cycle is maintained in biological environments. To test our hypothesis, we incubated model EPFRs with the fluorescent probe dihydrorhodamine (DHR). Marked increases in DHR fluorescence were observed. Using a more specific assay, hydroxyl radicals ( •OH) were also detected, and their level was further increased by cotreatment with thiols or ascorbic acid (AA), known components of epithelial lining fluid. Next, we incubated our model EPFR in bronchoalveolar lavage fluid (BALF) or serum. Detection of EPFRs and •OH verified that PM generate ROS in biological fluids. Moreover, incubation of pulmonary epithelial cells with EPFR-containing PM increased •OH levels compared to those in PM lacking EPFRs. Finally, measurements of oxidant injury in neonatal rats exposed to EPFRs by inhalation suggested that EPFRs induce an oxidant injury within the lung lining fluid and that the lung responds by increasing antioxidant levels. In summary, our EPFR-containing PM redox cycle to produce ROS, and these ROS are maintained in biological fluids and environments. Moreover, these ROS may modulate toxic responses of PM in biological tissues such as the lung. © 2013 American Chemical Society

Radical-containing ultrafine particulate matter initiates epithelial-to-mesenchymal transitions in airway epithelial cells

Environmentally persistent free radicals (EPFRs) in combustion generated particulate matter (PM) are capable of inducing pulmonary pathologies and contributing to the development of environmental asthma. In vivo exposure of infant rats to EPFRs demonstrates their ability to induce airway hyperresponsiveness to methacholine, a hallmark of asthma. However, the mechanisms by which combustion-derived EPFRs elicit in vivo responses remain elusive. In this study, we used a chemically defined EPFR consisting of approximately 0.2 μm amorphrous silica containing 3% cupric oxide with the organic pollutant 1,2-dichlorobenzene (DCB-230). DCB-230 possesses similar radical content to urban-collected EPFRs but offers several advantages, including lack of contaminants and chemical uniformity. DCB-230 was readily taken up by BEAS-2B and at high doses (200 μg/cm2) caused substantial necrosis. At low doses (20 μg/cm2), DCB-230 particles caused lysosomal membrane permeabilization, oxidative stress, and lipid peroxidation within 24 hours of exposure. During this period, BEAS-2B underwent epithelial-to-mesenchymal transition (EMT), including loss of epithelial cell morphology, decreased E-cadherin expression, and increased α-smooth muscle actin (α-SMA) and collagen I production. Similar results were observed in neonatal air-liquid interface culture (i.e., disruption of epithelial integrity and EMT). Acute exposure of infant mice to DCB-230 resulted in EMT, as confirmed by lineage tracing studies and evidenced by coexpression of epithelial E-cadherin and mesenchymal α-SMA proteins in airway cells and increased SNAI1 expression in the lungs. EMT in neonatal mouse lungs after EPFR exposure may provide an explanation for epidemiological evidence supporting PM exposure and increased risk of asthma. Copyright © 2013 by the American Thoracic Society

Long-rising Type II Supernovae in the Zwicky Transient Facility Census of the Local Universe

SN 1987A was an unusual hydrogen-rich core-collapse supernova originating from a blue supergiant star. Similar blue supergiant explosions remain a small family of events, and are broadly characterized by their long rises to peak. The Zwicky Transient Facility (ZTF) Census of the Local Universe (CLU) experiment aims to construct a spectroscopically complete sample of transients occurring in galaxies from the CLU galaxy catalog. We identify 13 long-rising (>40 days) Type II supernovae from the volume-limited CLU experiment during a 3.5 year period from June 2018 to December 2021, approximately doubling the previously known number of these events. We present photometric and spectroscopic data of these 13 events, finding peak r-band absolute magnitudes ranging from -15.6 to -17.5 mag and the tentative detection of Ba II lines in 9 events. Using our CLU sample of events, we derive a long-rising Type II supernova rate of $1.37^{+0.26}_{-0.30}\times10^{-6}$ Mpc$^{-3}$ yr$^{-1}$, $\approx$1.4% of the total core-collapse supernova rate. This is the first volumetric rate of these events estimated from a large, systematic, volume-limited experiment.Comment: 32 pages, 17 figures, 5 tables. Submitted to Ap

New Strategies for Combining Mindfulness with Integrative Cognitive Behavioral Therapy for the Treatment of Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) severely impacts social functioning, distress levels, and utilization of medical care compared with that of other major psychiatric disorders. Neither pharmacological nor psychotherapy interventions have adequately controlled cardinal symptoms of GAD: pervasive excessive anxiety and uncontrollable worry. Research has established cognitive behavioral therapy (CBT) as the most effective psychotherapy for controlling GAD; however, outcomes remain at only 50% reduction, with high relapse rates. Mindfulness has been integrated with CBT to treat people suffering from numerous psychiatric disorders, with mindfulness based stress reduction (MBSR) being the most researched. Preliminary evidence supports MBSR’s potential for controlling GAD symptoms and key researchers suggest mindfulness practices possess key elements for treating GAD. Classical mindfulness (CM) differs significantly from MBSR and possesses unique potentials for directly targeting process and state GAD symptoms inadequately treated by CBT. This article introduces the theory and practice of CM, its differences from MBSR, and a critical review of MBSR and CBT treatments for GAD. CM strategies designed to complement CBT targeting cardinal GAD symptoms are outlined with a case study illustrating its use