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

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

Model Combustion-Generated Particulate Matter Containing Persistent Free Radicals Redox Cycle to Produce Reactive Oxygen Species

[Image: see text] Particular 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 co-treatment 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 PM lacking EPFRs. Finally, measurements of oxidant injury in neonatal rats exposed to EPFRs by inhalation suggested that EPFRs induce an oxidant injury within 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

Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure.

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor

Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor

Reproducibility Project: Psychology

Reproducibility is a defining feature of science, but the extent to which it characterizes current research is unknown. We conducted replications of 100 experimental and correlational studies published in three psychology journals using high-powered designs and original materials when available

The DUNE Far Detector Vertical Drift Technology, Technical Design Report

International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

The DUNE Far Detector Vertical Drift Technology, Technical Design Report

International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals