55 research outputs found
Effects of Chemical Inducers on Larval Oyster Settlement in Suboptimal Conditions
Corresponding author (Biological Science): Alexz Carpenter, [email protected]://egrove.olemiss.edu/pharm_annual_posters_2022/1005/thumbnail.jp
Effect of Ploidy on Early Oyster Life Stage Tolerance of Salinity and Temperature
Corresponding author (BioMolecular Sciences): Christian Boudreaux, [email protected]://egrove.olemiss.edu/pharm_annual_posters_2022/1003/thumbnail.jp
Negative impacts of flood-associated water quality stressors on early oyster life stages
Presenter: Jessica Pruetthttps://egrove.olemiss.edu/pharm_annual_posters_2021/1008/thumbnail.jp
Effect of ploidy on salinity and temperature tolerance in early life stages of the Eastern oyster (\u3ci\u3eCrassostrea virginica\u3c/i\u3e)
The U.S. Gulf of Mexico contains the largest remaining wild oyster fishery in the world, but populations have declined in recent decades. A growing interest in off-bottom aquaculture that relies on triploid eastern oysters (Crassostrea virginica) has emerged in the Gulf region, yet these faster growing oysters suffer high mortality as adults during low salinity (\u3c5) events in warmer summer months. The combined effects of low salinity and high temperature stress on early life stages of triploid oysters are unknown. Early life stages are particularly crucial to understand because triploid oysters do not occur naturally and must be reared in hatchery settings, requiring appropriate water conditions to yield the greatest survival and growth. Thus, we tested the effects of different temperatures (28 ºC and 32 ºC) and salinities (5, 10, and 15) on diploid and triploid oysters at three critical production stages: veliger, pediveliger, and spat. Veliger survival was significantly lower for triploids relative to diploid oysters at all experimental conditions, but triploid veligers had faster growth than diploids at 32 ºC and salinity of 15. Pediveliger settlement was not affected by ploidy type and was reduced only at high temperature (32 ºC) and the lowest salinity (5). Diploid spat showed highest survival at 28 ºC and 15 salinity, while triploids survived best at 32 ºC and 15 salinity. Triploid spat attained greater shell height compared to diploids in our 6- day exposures, but growth decreased for both ploidies at lower salinities. At the salinity and temperature levels examined, diploid early life stages performed best at 28 ºC and 15 salinity, whereas triploids were more successful at 32 ºC and 15 salinity. A broader understanding of the combined effects of environmental stressors will improve the success of hatchery production yields and the resulting economic and environmental benefits of the oyster industry
Disentangling the Black Hole Mass Spectrum with Photometric Microlensing Surveys
From the formation mechanisms of stars and compact objects to nuclear
physics, modern astronomy frequently leverages surveys to understand
populations of objects to answer fundamental questions. The population of dark
and isolated compact objects in the Galaxy contains critical information
related to many of these topics, but is only practically accessible via
gravitational microlensing. However, photometric microlensing observables are
degenerate for different types of lenses, and one can seldom classify an event
as involving either a compact object or stellar lens on its own. To address
this difficulty, we apply a Bayesian framework that treats lens type
probabilistically and jointly with a lens population model. This method allows
lens population characteristics to be inferred despite intrinsic uncertainty in
the lens-class of any single event. We investigate this method's effectiveness
on a simulated ground-based photometric survey in the context of characterizing
a hypothetical population of primordial black holes (PBHs) with an average mass
of . On simulated data, our method outperforms current black hole
(BH) lens identification pipelines and characterizes different subpopulations
of lenses while jointly constraining the PBH contribution to dark matter to
\%. Key to robust inference, our method can marginalize over
population model uncertainty. We find the lower mass cutoff for stellar origin
BHs, a key observable in understanding the BH mass gap, particularly difficult
to infer in our simulations. This work lays the foundation for cutting-edge PBH
abundance constraints to be extracted from current photometric microlensing
surveys.Comment: 31 pages, 18 figures, submitted to AA
Training of child and adolescent psychiatry fellows in autism and intellectual disability
Patients with autism spectrum disorders and intellectual disability can be clinically complex and often have limited access to psychiatric care. Because little is known about post-graduate clinical education in autism spectrum disorder and intellectual disability, we surveyed training directors of child and adolescent psychiatry fellowship programs. On average, child and adolescent psychiatry directors reported lectures of 3 and 4 h per year in autism spectrum disorder and intellectual disability, respectively. Training directors commonly reported that trainees see 1-5 patients with autism spectrum disorder or intellectual disability per year for outpatient pharmacological management and inpatient treatment. Overall, 43% of directors endorsed the need for additional resources for training in autism spectrum disorder and intellectual disability, which, coupled with low didactic and clinical exposure, suggests that current training is inadequate
A Reanalysis of Public Galactic Bulge Gravitational Microlensing Events from OGLE-III and IV
Modern surveys of gravitational microlensing events have progressed to
detecting thousands per year. Surveys are capable of probing Galactic
structure, stellar evolution, lens populations, black hole physics, and the
nature of dark matter. One of the key avenues for doing this is studying the
microlensing Einstein radius crossing time distribution (). However,
systematics in individual light curves as well as over-simplistic modeling can
lead to biased results. To address this, we developed a model to simultaneously
handle the microlensing parallax due to Earth's motion, systematic instrumental
effects, and unlensed stellar variability with a Gaussian Process model. We
used light curves for nearly 10,000 OGLE-III and IV Milky Way bulge
microlensing events and fit each with our model. We also developed a forward
model approach to infer the timescale distribution by forward modeling from the
data rather than using point estimates from individual events. We find that
modeling the variability in the baseline removes a source of significant bias
in individual events, and previous analyses over-estimated the number of long
timescale ( days) events due to their over simplistic models ignoring
parallax effects and stellar variability. We use our fits to identify hundreds
of events that are likely black holes.Comment: Submitted version, in review, 33 pages, 18 figures, MCMC posterior
samples available by publisher after acceptanc
Lesbian fandom remakes the boy band
Lesbians and other queer women are typically absent from theorizations of boy band fandom even though boy bands often have sizable lesbian fan bases. Lesbian fandom of the British–Irish boy band One Direction congregated primarily on Tumblr; this fandom constituted a queer community space that exposed the boy band as a site of lesbian erotic and creative energy. One manifestation of lesbian One Direction fandom was the drag king performance group known as Every Direction, which maintained an active Tumblr page in addition to performing live drag king renditions of popular One Direction songs. Interviews with the group's members, along with a content analysis of lesbian Tumblr fandom of One Direction, illuminate the significant creative output of this understudied fan community. This phenomenon is placed into conversation with the lesbian feminist–affiliated Women's Music Movement of the 1970s, which had a lasting impact on popular conceptions of lesbian musical preferences in the United States. I argue that lesbian One Direction fandom constitutes a contemporary queer political intervention that reworks lesbian feminist political tactics and priorities. This data acts as a record of the lesbian One Direction fan community that congregated on Tumblr during the band's heyday, as well as an intervention in scholarly theorizations of lesbian fans and fan practices
Predator risk cue properties and environmental stress affect the importance of non-consumptive effects (NCEs) in salt marsh communities
Predators alter prey behavior and phenotype, which influences community structure and ecosystem function through cascading non-consumptive effects (NCEs). Prey reactive range, defined as the maximum distance at which prey detect and respond to predators, is a driving factor in determining the importance of NCEs. Thus, understanding the properties of risk cues used by prey to assess predation threat and how prey reactive ranges change across environmental stress gradients is necessary to elucidate where and when NCEs should regulate top-down controls. In this dissertation, I first describe the nature of predator risk cues used by a foundational species (the eastern oyster) in larval recruitment processes and an important grazer (mud snail) on intertidal mudflats. I found that injured prey cues alone and in combination with feeding predators cause unique oyster antipredator response in turbulent flow conditions as a result of quantitative and/or qualitative differences in predator risk cues. Mud snails had differential behavioral responses to two crab predator species in the lab but cascading blue crab NCEs had significant effects on benthic microalgae community composition in the field by behaviorally modifying species interactions in this non-linear 4-level food chain. Next, I focus on how estimating prey reactive ranges across environmental gradients may help predict the relative strength of predator consumptive effects (CEs) versus NCEs within a system using a blue crab-mud crab-oyster model food chain. Understanding how mud crab physical and sensory performance (i.e. mud crab reactive range) changed along a flow gradient led to accurate predictions on how the importance of blue crab CEs vs NCEs varied spatially and temporally within this oyster reef system. Thus, within systems, factors that structure communities can be predicted based on this understanding of how animal’s physical and sensory performance change across environmental stress gradients.Ph.D
Lesbian Fandom Remakes the Boy Band
Lesbians and other queer women are typically absent from theorizations of boy band fandom even though boy bands often have sizable lesbian fan bases. Lesbian fandom of the British–Irish boy band One Direction congregated primarily on Tumblr; this fandom constituted a queer community space that exposed the boy band as a site of lesbian erotic and creative energy. One manifestation of lesbian One Direction fandom was the drag king performance group known as Every Direction, which maintained an active Tumblr page in addition to performing live drag king renditions of popular One Direction songs. Interviews with the group's members, along with a content analysis of lesbian Tumblr fandom of One Direction, illuminate the significant creative output of this understudied fan community. This phenomenon is placed into conversation with the lesbian feminist–affiliated Women's Music Movement of the 1970s, which had a lasting impact on popular conceptions of lesbian musical preferences in the United States. I argue that lesbian One Direction fandom constitutes a contemporary queer political intervention that reworks lesbian feminist political tactics and priorities. This data acts as a record of the lesbian One Direction fan community that congregated on Tumblr during the band's heyday, as well as an intervention in scholarly theorizations of lesbian fans and fan practices
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