1,324 research outputs found
Low Variation in the Polymorphic Clock Gene Poly-Q Region Despite Population Genetic Structure across Barn Swallow (Hirundo rustica) Populations
No full textPubMed ID: 22216124This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Variability of the pharyngeal phase of swallow in the cat.
No full textOBJECTIVE:The pharyngeal phase of swallow has been thought to be a stereotypical motor behavior. STUDY DESIGN:This is a prospective, preclinical, hypothesis driven, one group by three-task design. METHODS:We sought to compare the effects of pharyngeal swabbing, water only, and water plus punctate mechanical stimulation on the spatiotemporal features of the pharyngeal phase of swallow in the cat. Swallow was elicited under these three conditions in six anaesthetized cats. Electromyographic activity was recorded from seven muscles used to evaluate swallow: mylohyoid, geniohyoid, thyrohyoid, thyroarytenoid, thyropharyngeus, cricopharyngeus, and parasternal. RESULTS:Pharyngeal swabbing in comparison to the other stimulus conditions, results in decreases in post-swallow cricopharyngeus activity (upper esophageal sphincter); a significant increase in parasternal (schluckatmung; swallow breath) activity; and increases in thyrohyoid (laryngeal elevator), thyroarytenoid (laryngeal adductor) and parasternal muscles burst duration. Pearson correlations were found of moderate strength between 19% of burst duration comparisons and weak to moderate relationships between 29% of burst amplitude comparisons. However, there were no positive significant relationships between phase durations and electromyogram amplitudes between any of the muscles studied during swallow. CONCLUSIONS:The results support the concept that a stereotypical behavior, such as pharyngeal swallowing in animal models, can be modified by sensory feedback from pharyngeal mucosal mechanoreceptors. Furthermore, differences in swallow phase durations and amplitudes provide evidence that separate regulatory mechanisms exist which regulate spatial and temporal aspects of the behavior
The Olasky Interview: Karen Swallow Prior on abolitionist Hannah More
No full textKaren Swallow Prior, a professor of English at Liberty University, is the author of Fierce Convictions: The Extraordinary Life of Hannah More -- Poet, Reformer, Abolitionist (Thomas Nelson, 2014)
Follow the Swallow
No full textChack the blackbird and Apollo the swallow are fledgling friends. Apollo explains that he is practising flying to Africa - but Chack doesn't believe him. Chack tells Apollo that the blossom on his favourite tree will eventually turn into orange berries - Apollo doesn't believe him. But, with the inevitable turning of the seasons, both birds learn to believe the other - and cement their friendship forever. A delightful tale from the author of The Gruffalo - Julia Donaldson
Fierce Convictions with Karen Swallow Prior
No full textThe StoryMen welcome author and professor Karen Swallow Pryor to introduce us to Hannah More, history’s forgotten abolitionist. We learn how Hannah’s passion for justice transformed 17th century England, why she was forgotten, and why we need to remember her today
Discovering Gold In The Greater Antilles – The Natural History And Breeding Biology Of The Hispaniolan Golden Swallow, Followed By The Status Of The Critically Endangered Jamaican Golden Swallow
No full textThis thesis is divided into two parts that collectively tell the contemporary stories of both Golden Swallow subspecies known to the Greater Antilles islands of Hispaniola and Jamaica. Part I constitutes the first in-depth look at the natural history and breeding biology of the Hispaniolan Golden Swallow derived from a three year study of a breeding population in the high-altitude pine forests of the Dominican Republic's Cordillera Central. The results and their respective discussions are extensive, and have therefore been organized in a more or less chronological format that adheres to particular stages of the breeding season. Some themes that have yet to be fully explored have also been included in order to highlight important gaps in our knowledge of the species. The idea behind this is simple - to inform the scientific community and public of what we know and what we still do not, the latter being just as important as the former, since this project was always designed to act as both a catalyst and a transparent, educational framework for future avian investigation in the Dominican Republic. Part II of the thesis declares the Jamaican subspecies of Golden Swallow extinct. This work concludes the long-term search (following Graves 2014) for the swallow, and should be received by conservationists and ornithologists in the Dominican Republic as a warning of how quickly an endemic species can be lost forever. Moreover, the extinction should be treated as motivation for improving local stewardship and scientific knowledge surrounding Hispaniola's avian species. ii
Studies on the management of the swallow bug, Oeciacus vicarius Horvath (Hemiptera: Cimicidae) and survival off its avian host
No full text2017 Spring.Includes bibliographical references.The swallow bug, Oeciacus vicarius Horvath is a common ectoparasite primarily associated with cliff swallows, Petrochelidon pyrrhonota (Vieillot). When the mud nests of the cliff swallows are constructed on homes and businesses, swallow bugs often readily enter attics or livable space after the host birds migrate and can cause serious episodes where they may bite humans. To better manage problem situations with swallow bugs a series of studies were conducted to determine the survival of swallow bugs in the absence of their avian host and to evaluate potential methods to monitor and control swallow bugs that do enter buildings. Swallow nests were collected in 2014 and 2015 immediately after nest abandonment and the nest contents sampled periodically for arthropods. Highest numbers of swallow bugs were found in the first sample dates, immediately after collection, averaging 269 swallow bugs/nest in 2014 and 297 swallow bugs/nest in 2015. Numbers of swallow bugs recovered declined sharply in later samples, with reductions at six months of 97.4% of the adults and 96.7% of the nymphs in the 2014 study, and reductions of 81.9% of the adults and 73.7% of the nymphs died in the 2015 study. At 12 months following collection, numbers of adults and nymphs had declined 99% and 98.3% in the 2014 study and 91.7% and 96.1% in the 2015 study. Other notable arthropods recovered from nests included the dermestid Trogoderma simplex Jayne, immature salticid spiders, and the bird flea Ceratophyllus petrochelidoni Wagner. Four traps were evaluated for their ability to capture swallow bugs in an arena test with an introduced swallow bug: a sticky card trap with no attractant (CatchMaster 288i), a carbon dioxide based trap with a collection cup (Bedbug Beacon), a carbon dioxide and heat trap with a bed bug pheromone on a sticky card (Biocare First Response Bed Bug Monitor), and a bed bug pheromone attractant trap with a collecting cup (SenSci Volcano). None of the traps containing attractants showed evidence that they were able to attract swallow bugs. The CatchMaster 288i and BedBug Beacon traps did work well as a passive monitoring device but both the Biocare First Response Monitor and SenSci Volcano SC caught few swallow bugs either because of trap design that allowed the insects to readily escape or prevented their capture due to poor adhesive properties of the glue. Follow-up studies were conducted to evaluate potential attractants in bioassay choice tests, including heat, carbon dioxide, and odors associated with swallow bugs. None of these traps showed evidence of attraction to swallow bugs, suggesting that swallow bugs may use different cues to located hosts than do bed bugs. Efficacies of insecticides for control of swallow bugs were tested in laboratory trials. Treatments included Suspend Polyzone (deltamethrin), Talstar Professional (bifenthrin), Onslaught Fastcap (esfenvalerate, prallethrin, piperonyl butoxide), Temprid (imidacloprid, cyfluthrin), and Phantom (chlorfenapyr). All of the pyrethroid containing insecticides showed good ability to kill swallow bugs, typically killing 100 percent of the test insects within one week. Lower mortality was observed with chlorfenapyr
Effect of swallow stimuli on normalized electromyogram amplitude (% of maximum) and durations (ms) of selected swallow-related muscles, over the three stimulus conditions.
No full text<p>*Significant effect (repeated measures ANOVA, P<0.05), significant difference (post-hoc test) from both other stimuli conditions (P<0.05).</p><p>Effect of swallow stimuli on normalized electromyogram amplitude (% of maximum) and durations (ms) of selected swallow-related muscles, over the three stimulus conditions.</p
Shipping costs and inflation()
No full textThe Covid-19 pandemic has disrupted global supply chains, leading to shipment delays and soaring shipping costs. We study the impact of global shipping costs—measured by the Baltic Dry Index (BDI)—on domestic prices for a large panel of countries during the period 1992–2021. We find that spikes in the BDI are followed by sizable and statistically significant increases in import prices, PPI, headline, and core inflation, as well as inflation expectations. The impact is similar in magnitude but more persistent than for shocks to global oil and food prices. The effects are more muted in countries where imports make up a smaller share of domestic consumption, and those with inflation targeting regimes and better-anchored inflation expectations. The results are robust to several checks, including an instrumental variables approach in which changes in shipping costs are instrumented with an indicator of closures of the Suez Canal
Eco-Labeling and the Price Premium
No full textInternational environmental and government organizations propose eco-labeling as a market incentive to cause industry to operate in an ecologically sustainable and biodiversity-friendly manner. A microeconomic analysis questions whether eco-labeling will cause producer profits in a competitive industry to decline, even under a voluntary system, and whether eco-labeling will necessarily generate different prices for labeled and unlabeled product. Using wood product as an example, results identify conditions that may exist when firms lose profits, even under a voluntary system, and where existing production constraints may lead to a single price, regardless of labeling.
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