2,924 research outputs found

    INFLUENCE OF TASTE AND COLOR CUES ON BATHING BY STARLINGS IN APPETITIVE AND ADVERSIVE CONTEXTS: IMPLICATIONS FOR ANIMAL DAMAGE CONTROL

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    The importance of color and taste in feeding and drinking by omnivorous birds is context·dependent and influenced by learning. Here, we report three experiments designed to assess the influence of such characteristics on starlings. In Experiment 1, eight starlings were given a choice between bathing in red or plain water and 0.15 M NaCI solution or plain water. The frequencies of bathing, drinking, and preening were recorded. Red water was avoided (p \u3c 0.05), but no preferences were observed between NaCI solution and plain water (p \u3e 0.25). That 0.15 M NaCI was not avoided is surprising, because it is rejected by starlings when drinking. Perhaps starlings do not taste substances while bathing but continue to ingest substances that they would otherwise reject. In Experiment 2, we assessed these alternative explanations and also tested (a) whether starlings would bathe in colored water if plain water was unavailable, (b) whether starlings would show preferences among such colors, and (c) whether preferences courd be altered by learning. Twenty-four starlings were assigned to three conditions. Birds in the first condition were presented with red and blue baths and relative preferences for bathing in these colors were assessed. Birds in the second condition were presented with a blue bath and intubated with methiocarb or propylene glycol. Birds in the third condition were presented with a saccharin bath and intubated with methiocarb or propylene glycol. On the four days following treatment, birds in the second condition were given two-choice tests between red and blue baths. Those in the third condition were given two-choice tests between bathing in saccharin solution and plain water. Birds readily bathed in red and blue water when plain water was unavailable. After treatment, however, birds avoided blue water (p \u3c 0.05), but aversions dissipated rapidly. Learned aversions for saccharin were also obtained (p \u3c 0.05); these remained strong over all tests. Experiment 3 was designed to assess the differential importance of taste and color. Sixteen starlings were aSSigned to four groups. Two groups were food-deprived and then given dogfood in a red cup followed by a bath of 0.15 M NaCI or LiCI. The other two groups were presented with a bath of 0.15 M NaCI or LiCI only, as a control. On the four days immediately following treatment, all groups were given two-choice feeding (red vs. blue food cups) and bathing (NaCI vs. plain water) tests. Aversions were expressed towards color in the feeding context (p \u3c 0.05) but not taste in the bathing context (p \u3e 0.25). We inferred that color cues in the feeding context overshadowed taste cues in the bathing context. The present results may have implications for control. Starlings will bathe even under harsh environmental conditions, and one control strategy might be to pair livestock feed with distinctive colors and provide lithium·adulterated bathing stations nearby. Starlings eating feed and bathing in the solution might form color aversions and subsequently avoid the food. Also, the use of such techniques might enhance already existing control, such as the use of starlicide baits. Depredating starlings would be directed toward such baits as birds feeding in the laboratory are directed towards food color combinations not explicitly paired with lithium-induced malaise

    PRELIMINARY EVALUATION OF A GRANULAR TRIMETHACARB FORMULATION FOR DETERRING GRAZING BY AMERICAN COOTS

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    In a 0.2 ha flight pen, groups of 4 American coots were tested to determine if their grazing activity could be affected by application of a registered granular-trimethacarb insecticide. In the 3 days following treatment (3 kg/ha, a.i.), grazing activity in the treated portions of the 200 m2 experimental plots was reduced an average of 47X. Overall use of the treated areas followed a similar pattern but was less consistent among groups. The addition of methylpyrazine, a strong odorant, produced a strong initial suppression of grazing activity in the treated halves of the plots. However, subsequent rain and a change in the coots\u27 grazing behavior prevented a definitive evaluation of the methylpyrazine treatment. Two birds that died during the trimethacarb-only portion of the study did not have abnormally low levels of brain cholinesterase. However, this finding does not preclude the possibility that they were unable to distinguish treated from untreated grass and consumed lethal amounts of trimethacarb. Additional investigation of methylpyrazine appears warranted; such materials may act to decrease the likelihood that birds will ingest lethal quantities of repellent

    Evolutionary innovation and diversification of carotenoid-based pigmentation in finches

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    © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution. The ornaments used by animals to mediate social interactions are diverse, and by reconstructing their evolutionary pathways we can gain new insights into the mechanisms underlying ornamental innovation and variability. Here, we examine variation in plumage carotenoids among the true finches (Aves: Fringillidae) using biochemical and comparative phylogenetic analyses to reconstruct the evolutionary history of carotenoid states and evaluate competing models of carotenoid evolution. Our comparative analyses reveal that the most likely ancestor of finches used dietary carotenoids as yellow plumage colorants, and that the ability to metabolically modify dietary carotenoids into more complex pigments arose secondarily once finches began to use modified carotenoids to create red plumage. Following the evolutionary “innovation” that enabled modified red carotenoid pigments to be deposited as plumage colorants, many finch species subsequently modified carotenoid biochemical pathways to create yellow plumage. However, no reversions to dietary carotenoids were observed. The finding that ornaments and their underlying mechanisms may be operating under different selection regimes—where ornamental trait colors undergo frequent reversions (e.g., between red and yellow plumage) while carotenoid metabolization mechanisms are more conserved—supports a growing empirical framework suggesting different evolutionary patterns for ornaments and the mechanistic innovations that facilitate their diversification

    The role of a disulfide bridge in the stability and folding kinetics of Arabidopsis thaliana cytochrome c6A

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    Cytochrome c 6A is a eukaryotic member of the Class I cytochrome c family possessing a high structural homology with photosynthetic cytochrome c 6 from cyanobacteria, but structurally and functionally distinct through the presence of a disulfide bond and a heme mid-point redox potential of + 71 mV (vs normal hydrogen electrode). The disulfide bond is part of a loop insertion peptide that forms a cap-like structure on top of the core α-helical fold. We have investigated the contribution of the disulfide bond to thermodynamic stability and (un)folding kinetics in cytochrome c 6A from Arabidopsis thaliana by making comparison with a photosynthetic cytochrome c 6 from Phormidium laminosum and through a mutant in which the Cys residues have been replaced with Ser residues (C67/73S). We find that the disulfide bond makes a significant contribution to overall stability in both the ferric and ferrous heme states. Both cytochromes c 6A and c 6 fold rapidly at neutral pH through an on-pathway intermediate. The unfolding rate for the C67/73S variant is significantly increased indicating that the formation of this region occurs late in the folding pathway. We conclude that the disulfide bridge in cytochrome c 6A acts as a conformational restraint in both the folding intermediate and native state of the protein and that it likely serves a structural rather than a previously proposed catalytic role. © 2011 Elsevier B.V. All rights reserved

    ‘In the shower crying ...but we came back in the following day and did it all again’. Distress and resilience in care home staff during the COVID-19 pandemic – A qualitative interview study.

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    Abstract:\ua9 The Author(s) 2024.Background: Care homes (long-term care facilities) were profoundly impacted early in the COVID-19 pandemic, both in terms of resident mortality and restrictions for infection control. This study investigated the impact on the emotional well-being of care home staff of challenges faced at this time, and the strategies used to manage them. Methods: Semi-structured interviews conducted October 2020-June 2021 with care home staff and health service staff working with them explored the impact of the early waves of the COVID-19 pandemic (March 2020-June 2021). Interview data were analysed using reflexive thematic analysis. Results: Interview participants were 16 care home staff and 10 health service staff. Analysis generated four key themes: 1)Anxiety and distress, 2)Overwhelming workload, 3)Pulling through; and 4)Resilience in a time of crisis. Care home staff experienced Anxiety and distress due to uncertainty of what to expect; witnessing illness and deaths of residents; concerns regarding their own health, and sometimes feeling their work was under-recognised. They also experienced an Overwhelming workload due to infection control measures, caring for sick residents and reduction in external healthcare support. Our theme of Pulling through reflects the peer support and problem-solving strategies with which care home staff managed the impact of the pandemic, along with a sense of responsibility and meaning towards their work. An overarching theme of Resilience in a time of crisis drew on the other three themes and describes how many staff managed, maintained, and often increased their work despite the challenges of the pandemic. Participants also described increasing emotional fatigue as the pandemic continued. Conclusions: This paper builds on literature on the emotional impact of the pandemic on care home staff, also exploring ways that staff responded to this impact. These findings can help inform planning for future crises including disease outbreaks, and raise important questions for further work to develop pandemic preparedness in care homes and beyond. They also raise wider questions about the current cultural status of care work, which may have exposed care home staff to greater risk of distress, and which contrasts with the professionalism and responsibility shown by staff in response to pandemic challenge

    Comet 17P/Holmes in Outburst: The Near Infrared Spectrum

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    Jupiter family comet 17P/Holmes underwent a remarkable outburst on UT 2007 Oct. 24, in which the integrated brightness abruptly increased by about a factor of a million.We obtained near infrared (0.8 - 4.2 micron) spectra of 17P/Holmes on UT 2007 Oct. 27, 28 and 31, using the 3.0-m NASA Infrared Telescope Facility (IRTF) atop Mauna Kea. Two broad absorption bands were found in the reflectance spectra with centers (at 2 micron and 3 micron, respectively) and overall shapes consistent with the presence of water ice grains in the coma. Synthetic mixing models of these bands suggest an origin in cold ice grains of micron size. Curiously, though, the expected 1.5 micron band of water ice was not detected in our data, an observation for which we have no explanation. Simultaneously, excess thermal emission in the spectra at wavelengths beyond 3.2 micron has a color temperature of 360 +/- 40 K (corresponding to a superheat factor of ~ 2.0 +/- 0.2 at 2.45 AU). This is too hot for these grains to be icy. The detection of both water ice spectral features and short-wavelength thermal emission suggests that the coma of 17P/Holmes has two components (hot, refractory dust and cold ice grains) which are not in thermal contact. A similarity to grains ejected into the coma of 9P/Tempel 1 by the Deep Impact spacecraft is noted.Comment: 27 pages, 11 figures, accepted for publication in A

    ‘In the shower crying
but we came back in the following day and did it all again’. Distress and resilience in care home staff during the COVID-19 pandemic– A qualitative interview study

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    Background Care homes (long-term care facilities) were profoundly impacted early in the COVID-19 pandemic, both in terms of resident mortality and restrictions for infection control. This study investigated the impact on the emotional well-being of care home staff of challenges faced at this time, and the strategies used to manage them. Methods Semi-structured interviews conducted October 2020-June 2021 with care home staff and health service staff working with them explored the impact of the early waves of the COVID-19 pandemic (March 2020-June 2021). Interview data were analysed using reflexive thematic analysis. Results Interview participants were 16 care home staff and 10 health service staff. Analysis generated four key themes: 1)Anxiety and distress, 2)Overwhelming workload, 3)Pulling through; and 4)Resilience in a time of crisis. Care home staff experienced Anxiety and distress due to uncertainty of what to expect; witnessing illness and deaths of residents; concerns regarding their own health, and sometimes feeling their work was under-recognised. They also experienced an Overwhelming workload due to infection control measures, caring for sick residents and reduction in external healthcare support. Our theme of Pulling through reflects the peer support and problem-solving strategies with which care home staff managed the impact of the pandemic, along with a sense of responsibility and meaning towards their work. An overarching theme of Resilience in a time of crisis drew on the other three themes and describes how many staff managed, maintained, and often increased their work despite the challenges of the pandemic. Participants also described increasing emotional fatigue as the pandemic continued. Conclusions This paper builds on literature on the emotional impact of the pandemic on care home staff, also exploring ways that staff responded to this impact. These findings can help inform planning for future crises including disease outbreaks, and raise important questions for further work to develop pandemic preparedness in care homes and beyond. They also raise wider questions about the current cultural status of care work, which may have exposed care home staff to greater risk of distress, and which contrasts with the professionalism and responsibility shown by staff in response to pandemic challenges

    Novae Ejecta as Colliding Shells

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    Following on our initial absorption-line analysis of fifteen novae spectra we present additional evidence for the existence of two distinct components of novae ejecta having different origins. As argued in Paper I one component is the rapidly expanding gas ejected from the outer layers of the white dwarf by the outburst. The second component is pre-existing outer, more slowly expanding circumbinary gas that represents ejecta from the secondary star or accretion disk. We present measurements of the emission-line widths that show them to be significantly narrower than the broad P Cygni profiles that immediately precede them. The emission profiles of novae in the nebular phase are distinctly rectangular, i.e., strongly suggestive of emission from a relatively thin, roughly spherical shell. We thus interpret novae spectral evolution in terms of the collision between the two components of ejecta, which converts the early absorption spectrum to an emission-line spectrum within weeks of the outburst. The narrow emission widths require the outer circumbinary gas to be much more massive than the white dwarf ejecta, thereby slowing the latter's expansion upon collision. The presence of a large reservoir of circumbinary gas at the time of outburst is suggestive that novae outbursts may sometime be triggered by collapse of gas onto the white dwarf, as occurs for dwarf novae, rather than steady mass transfer through the inner Lagrangian point.Comment: 12 pages, 3 figures; Revised manuscript; Accepted for publication in Astrophysics & Space Scienc
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