691 research outputs found
Secrets of a Rare Bird: Breeding behavior of the Gray-breasted Flycatcher (Lathrotriccus griseipectus) in Ecuador
The Tumbesian region of southwestern Ecuador and northwestern Peru is home to a large number of endemic bird species. Many of these species are threatened with extinction, and little is known about their basic biology. Thus, information regarding natural history of species in the region is needed to guide conservation management. We studied the reproductive biology of the Gray-breasted Flycatcher, Lathrotriccus griseipectus, a small Tyrannid that lives in the Tumbesian region. Due to habitat destruction, the range size of L. griseipectus has dwindled and the species is now listed as Vulnerable on the IUCN Red List. We used a mounted camera to record for the first time the breeding behaviors of adults at the nest. We recorded 80 hours of activity across 7 days. We analyzed video footage for the amount of time adults cared for young and recorded fledging of the nestlings. We then compared these data to a species in the same genus, L. euleri, that is common and has a large range size to better understand difference between the two. By examining the breeding behavior of L. griseipectus, our work sheds light on reproduction of a rare, endemic species and provides critical information for conservation management plans
The Effects of Acute Ammonia Toxicity on Certain Homogram Parameters in Sheep
Due to the rapidly expanding human population, one of the greatest problems facing agricultural scientists is the development of adequate food resources to meet the growing demand for quality protein. The development of more economical and higher quality feed for ruminant animals is essential since they are one of man\u27s primary sources of animal protein. Microorganisms in the ruminant stomach convert relatively cheap non-protein nitrogen compounds into bacterial proteins, which are digested, absorbed, and utilized by the host animal. Urea, a common non-protein nitrogen compound, is hydrolyzed into ammonia and carbon dioxide by bacterial urease. When urea is hydrolyzed faster than it is utilized by bacteria, quantities of ammonia are absorbed through the rumen wall into the bloodstream. This normally creates no problem, since the ammonia is converted into urea by the liver, however, toxicity may occur if the blood ammonium-nitrogen (BAN) level surpasses the animal\u27s detoxification capacity. High levels of BAN are not only toxic, but result in an efficient utilization of nitrogen for protein synthesis. There have been extensive investigations involving the physiological, nutritional, and metabolic effects of an elevated BAN level. However, inadequate information is available concerning body fluid, differential tissue ammonia content, and blood hemogram quantities resulting from toxic BAN levels. The purpose of this investigation was to detect changes in the following hemogram parameters resulting from acute ammonia intoxication: packed cell volume (PCV), hemoglobin concentration (Hb), total red blood cell count (RBC), and total white blood cell count (WBC)
Seventy-Seven Sweet Songs and Thirty-Six Familiar Hymns and Gospel Songs: A Collection of Hymns and Tunes for Gospel Meetings and All Occasions of Christian Work and Worship.
https://digitalcommons.acu.edu/crs_books/1039/thumbnail.jp
Cluster Fragments in Amorphous Phosphorus and their Evolution under Pressure
Amorphous phosphorus (a-P) has long attracted interest because of its complex
atomic structure, and more recently as an anode material for batteries.
However, accurately describing and understanding a-P at the atomistic level
remains a challenge. Here we show that large-scale molecular-dynamics
simulations, enabled by a machine learning (ML)-based interatomic potential for
phosphorus, can give new insights into the atomic structure of a-P and how this
structure changes under pressure. The structural model so obtained contains
abundant five-membered rings, as well as more complex seven- and eight-atom
clusters. Changes in the simulated first sharp diffraction peak during
compression and decompression indicate a hysteresis in the recovery of
medium-range order. An analysis of cluster fragments, large rings, and voids
suggests that moderate pressure (up to about 5 GPa) does not break the
connectivity of clusters, but higher pressure does. Our work provides a
starting point for further computational studies of the structure and
properties of a-P, and more generally it exemplifies how ML-driven modeling can
accelerate the understanding of disordered functional materials
Limited Activity Of Miltefosine In Murine Models Of Cryptococcal Meningoencephalitis And Disseminated Cryptococcosis
Miltefosine is an alkyl phosphocholine with good oral bioavailability and in vitro activity against Cryptococcus species that has gained interest as an additional agent for cryptococcal infections. Our objective was to further evaluate the in vivo efficacy of miltefosine in experimental in vivo models of cryptococcal meningoencephalitis and disseminated cryptococcosis. Mice were infected intracranially or intravenously with either C. neoformans USC1597 or H99. Miltefosine treatment (1.8 to 45 mg/kg of body weight orally once daily) began at either 1 h or 1 day postinoculation. Fluconazole (10 mg/kg orally twice daily) or amphotericin B deoxycholate (3 mg/kg intraperitoneally once daily) served as positive controls. In our standard models, miltefosine did not result in significant improvements in survival or reductions in fungal burden against either C. neoformans isolate. There was a trend toward improved survival with miltefosine at 7.2 mg/kg against disseminated cryptococcosis with the H99 strain but only at a low infecting inoculum. In contrast, both fluconazole and amphotericin B significantly improved survival in mice with cryptococcal meningoencephalitis and disseminated cryptococcosis due to USC1597. Amphotericin B also improved survival against both cryptococcal infections caused by H99. Combination therapy with miltefosine demonstrated neither synergy nor antagonism in both models. These results demonstrate limited efficacy of miltefosine and suggest caution with the potential use of this agent for the treatment of C. neoformans infections.Pharmac
Changes in work habits of lifeguards in relation to Florida red tide
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Harmful Algae 9 (2010): 419-425, doi:10.1016/j.hal.2010.02.005.The marine dinoflagellate, Karenia brevis, is responsible for Florida red tides. Brevetoxins, the
neurotoxins produced by K. brevis blooms, can cause fish kills, contaminate shellfish, and lead
to respiratory illness in humans. Although several studies have assessed different economic
impacts from Florida red tide blooms, no studies to date have considered the impact on beach
lifeguard work performance. Sarasota County experiences frequent Florida red tides and staffs
lifeguards at its beaches 365 days a year. This study examined lifeguard attendance records
during the time periods of March 1 to September 30 in 2004 (no bloom) and March 1 to
September 30 in 2005 (bloom). The lifeguard attendance data demonstrated statistically
significant absenteeism during a Florida red tide bloom. The potential economic costs resulting
from red tide blooms were comprised of both lifeguard absenteeism and presenteeism. Our
estimate of the costs of absenteeism due to the 2005 red tide in Sarasota County is about 100,000 at Sarasota County beaches alone. When surveyed, lifeguards reported not
only that they experienced adverse health effects of exposure to Florida red tide but also that
their attentiveness and abilities to take preventative actions decrease when they worked during a
bloom, implying presenteeism effects. The costs of presenteeism, which imply increased risks to
beachgoers, arguably could exceed those of absenteeism by an order of magnitude. Due to the
lack of data, however, we are unable to provide credible estimates of the costs of presenteeism or
the potential increased risks to bathers.This research was supported by the National Science Foundation under The Research Experience
for Undergraduate Program, grant number 0453955; the P01 ES 10594, DHHS NIH of the
National Institute of Environmental Health Sciences; the Center for Oceans and Human Health at
the Woods Hole Oceanographic Institution [National Science Foundation (NSF) OCE-0430724;
National Institute of Environmental Health Sciences (NIEHS) P50 ES012742]; and the Ocean
and Human Health Center at the University of Miami Rosenstiel School (NSF 0CE0432368;
NIEHS 1 P50 ES12736)
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