4,353 research outputs found
Alien Registration- Plummer, J K. (Fort Fairfield, Aroostook County)
https://digitalmaine.com/alien_docs/35494/thumbnail.jp
The effects of subcurative praziquantel treatment on life-history traits and trade-offs in drug-resistant Schistosoma mansoni
Natural selection acts on all organisms, including parasites, to maximize reproductive fitness. Drug resistance traits are often associated with life-history costs in the absence of treatment. Schistosomiasis control programmes rely on mass drug administration to reduce human morbidity and mortality. Although hotspots of reduced drug efficacy have been reported, resistance is not widespread. Using Bayesian state-space models (SSMs) fitted to data from an in vivo laboratory system, we tested the hypothesis that the spread of resistant Schistosoma mansoni may be limited by life-history costs not present in susceptible counterparts. S. mansoni parasites from a praziquantel-susceptible (S), a praziquantel-resistant (R) or a mixed line of originally resistant and susceptible parasites (RS) were exposed to a range of praziquantel doses. Parasite numbers at each life stage were quantified in their molluscan intermediate and murine definitive hosts across four generations, and SSMs were used to estimate key life-history parameters for each experimental group over time. Model outputs illustrated that parasite adult survival and fecundity in the murine host decreased across all lines, including R, with increasing drug pressure. Trade-offs between adult survival and fecundity were observed in all untreated lines, and these remained strong in S with praziquantel pressure. In contrast, trade-offs between adult survival and fecundity were lost under praziquantel pressure in R. As expected, parasite life-history traits within the molluscan host were complex, but trade-offs were demonstrated between parasite establishment and cercarial output. The observed trade-offs between generations within hosts, which were modified by praziquantel treatment in the R line, could limit the spread of R parasites under praziquantel pressure. Whilst such complex life-history costs may be difficult to detect using standard empirical methods, we demonstrate that SSMs provide robust estimates of life-history parameters, aiding our understanding of costs and trade-offs of resistant parasites within this system and beyond
Mapping the Skies of Ultracool Worlds: Detecting Storms and Spots with Extremely Large Telescopes
Extremely large telescopes (ELTs) present an unparalleled opportunity to
study the magnetism, atmospheric dynamics, and chemistry of very low mass stars
(VLMs), brown dwarfs, and exoplanets. Instruments such as the Giant Magellan
Telescope - Consortium Large Earth Finder (GMT/GCLEF), the Thirty Meter
Telescope's Multi-Objective Diffraction-limited High-Resolution Infrared
Spectrograph (TMT/MODHIS), and the European Southern Observatory's Mid-Infrared
ELT Imager and Spectrograph (ELT/METIS) provide the spectral resolution and
signal-to-noise (S/N) necessary to Doppler image ultracool targets' surfaces
based on temporal spectral variations due to surface inhomogeneities. Using our
publicly-available code, , developed and validated in Plummer & Wang
(2022), we evaluate these instruments' abilities to discern magnetic star spots
and cloud systems on a VLM star (TRAPPIST-1); two L/T transition ultracool
dwarfs (VHS J12561257 b and SIMP J0136+0933); and three exoplanets (Beta Pic
b and HR 8799 d and e). We find that TMT/MODHIS and ELT/METIS are suitable for
Doppler imaging the ultracool dwarfs and Beta Pic b over a single rotation.
Uncertainties for longitude and radius are typically , and
latitude uncertainties range from .
TRAPPIST-1's edge-on inclination and low provide a challenge
for all three instruments while GMT/GCLEF and the HR 8799 planets may require
observations over multiple rotations. We compare the spectroscopic technique,
photometry-only inference, and the combination of the two. We find combining
spectroscopic and photometric observations can lead to improved Bayesian
inference of surface inhomogeneities and offers insight into whether ultracool
atmospheres are dominated by spotted or banded features.Comment: Accepted for publication in The Astrophysical Journal, 26 pages, 10
figures, 3 table
A Unified Spectroscopic and Photometric Model to Infer Surface Inhomogeneity: Application to Luhman 16B
Extremely large telescopes (ELTs) provide an opportunity to observe surface
inhomogeneities for ultracool objects including M dwarfs, brown dwarfs (BDs),
and gas giant planets via Doppler imaging and spectro-photometry techniques.
These inhomogeneities can be caused by star spots, clouds, and vortices. Star
spots and associated stellar flares play a significant role in habitability,
either stifling life or catalyzing abiogenesis depending on the emission
frequency, magnitude, and orientation. Clouds and vortices may be the source of
spectral and photometric variability observed at the L/T transition of BDs and
are expected in gas giant exoplanets. We develop a versatile analytical
framework to model and infer surface inhomogeneities which can be applied to
both spectroscopic and photometric data. This model is validated against a slew
of numerical simulations. Using archival spectroscopic and photometric data, we
infer star spot parameters (location, size, and contrast) and generate global
surface maps for Luhman 16B (an early T dwarf and one of our solar system's
nearest neighbors at a distance of approximately 2 pc). We confirm previous
findings that Luhman 16B's atmosphere is inhomogeneous with time-varying
features. In addition, we provide tentative evidence of longer timescale
atmospheric structures such as dark equatorial and bright mid-latitude to polar
spots. These findings are discussed in the context of atmospheric circulation
and dynamics for ultracool dwarfs. Our analytical model will be valuable in
assessing the feasibility of using ELTs to study surface inhomogeneities of gas
giant exoplanets and other ultracool objects.Comment: 23 pages, 10 figures, 1 table. Accepted for publication in The
Astrophysical Journa
Protein expression of G-protein inwardly rectifying potassium channels (GIRK) in breast cancer cells
Background
Previous data from our laboratory has indicated that a functional link exists between the G-protein-coupled inwardly rectifying potassium (GIRK) channel and the beta-adrenergic receptor pathway in breast cancer cell lines, and these pathways were involved in growth regulation of these cells. Alcohol is an established risk factor for breast cancer and has been found to open GIRK. In order to further investigate GIRK channels in breast cancer and possible alteration by ethanol, we identified GIRK channel protein expression in breast cancer cells. Results
Cell pellets were collected and membrane protein was isolated to determine GIRK protein expression. GIRK protein was also analyzed by immuno-precipitation. GIRK protein was over-expressed in cells by transfection of GIRK plasmids. Gene expression studies were done by real-time RT-PCR. GIRK protein expression was identified in breast cancer cell lines. Expression of GIRK1 at the indicated molecular weight (MW) (62 kDa) was seen in cell lines MDA-MB-453 and ZR-75-1. In addition, GIRK1 expression was seen at a lower MW (40–42 kDa) in MDA-MB-361, MDA-MB-468, MCF-7, ZR-75-1, and MDA-MB-453 cell lines. To prove the lower MW protein was GIRK1, MDA-MB-453 cells were immuno-precipitated. GIRK2 expression was seen in MDA-MB-468, MCF-7, and ZR-75-1 and was variable in MDA-MB-453, while GIRK4 protein expression was seen in all six cell lines tested. This is the first report indicating GIRK protein expression in breast cancer cells. To determine functionality, MDA-MB-453 cells were stimulated with ethanol. Decreased GIRK1 protein expression levels were seen after treatment with 0.12% ethanol in MDA-MB-453 breast cancer cells. Serum-free media decreased GIRK protein expression, possibly due to lack of estrogen in the media. Transfection of GIRK1 or GIRK4 plasmids increased GIRK1 protein expression and decreased gene expression in MDA-MB-453 breast cancer cells. Conclusion
Our data indicates that functional GIRK channels exist in breast cancer cells that are involved in cellular signaling
Effects of Alparazolam and Triazolam on Isolation-Induced Aggression in Rats
Author Institution: Department of Biology, Western Michigan UniversityThe efficacy of two new benzodiazepine tranquilizers, alprazolam and triazolam, in the reduction of aggression produced in rats by isolation was tested. Rats were isolated for at least three weeks. They were then placed in a cage with another rat, and aggressive and submissive behaviors that occurred were noted. Several of the behaviors were changed by either alprazolam or triazolam. Aggressive behaviors of thrust, attack, offensive upright, and offensive sideways were decreased; bite was increased. The submissive behavior of defensive sideways was decreased, whereas crouch and freeze were increased. Reduction in aggression seems consistent with results for other benzodiazepine tranquilizers such as diazepam and chlordiazepoxide
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