Seasonal species assemblages in seagrass habitats of northeast Pamlico Sound

Large estuarine habitats support a wide variety different species that use these areas for habitat. However, species assemblages are still poorly described over large areas of estuarine habitat. The underrepresentation of species assemblages in estuarine habitats in the literature leaves room for research inquiring about how and why these assemblages are occurring. The objective of this study was to assess how estuarine habitat type and location, as well as season, influences nekton and invertebrate community diversity and composition, within Pamlico Sound. Sampling was conducted across four dates between the summer and fall of 2022 to encompass greater variations in species compositions in the Pamlico Sound. I initially hypothesized that seagrass habitats would have higher species abundance, richness, and overall diversity compared to unvegetated habitat. I also hypothesized that abundance and richness would decline with seasonality, and that seagrass areas spatially closer to ocean inlets would have a higher richness and abundance than areas further into the sound. In this study, I analyze a novel dataset collected in the northeast part of Pamlico Sound, North Carolina in the area between Oregon Inlet, Roanoke Sound, and Croatan Sound. The dataset is from a beach seine sampling survey of fish and invertebrate assemblages within seagrass habitats, and adjacent unvegetated habitats, that I collected over the course of 2022. YSI data collected from each sampling location, including temperature, salinity, and dissolved oxygen (DO), was used to characterize species compositions across sampling sites. A paired t-test found statistically significant differences between vegetated seagrass habitats and unvegetated seagrass habitats in both species richness and species abundance, while an analysis of variance (ANOVA) found significant differences in richness and abundance over time in seagrass habitats. Indeed, in paired beach seine hauls, the abundance of fish and invertebrates was an order of magnitude higher over seagrass compared to the adjacent unvegetated bottom. In the months between summer and fall, there was a general decline in nekton abundance. Abundance and richness also declined as the distance from Oregon Inlet increased. Species composition consisted of five dominant species, pinfish, pigfish, silver perch, bay anchovy, and Atlantic silversides. This study will inform fisheries and management groups local to North Carolina’s coastline about changes in species assemblages and their whereabouts within the sound. This study will also serve as a baseline for further research of species assemblages within Pamlico Sound

Optimal Restricted Estimation for More Efficient Longitudinal Causal Inference

Efficient semiparametric estimation of longitudinal causal effects is often analytically or computationally intractable. We propose a novel restricted estimation approach for increasing efficiency, which can be used with other techniques, is straightforward to implement, and requires no additional modeling assumptions

Vacuum torque, propulsive forces, and anomalous tangential forces: Effects of nonreciprocal media out of thermal equilibrium

From the generalized fluctuation-dissipation theorem, it is known that a body at rest made of nonreciprocal material may experience a torque, even in vacuum, if it is not in thermal equilibrium with its environment. However, it does not experience self-propulsion in such circumstances, except in higher order. Nevertheless, such a body may experience both a normal torque and a lateral force when adjacent to an ordinary surface with transverse translational symmetry. We explore how these phenomena arise, discuss what terminal velocities might be achieved, and point out some of the limitations of applying our results to observations, including the Lorenz-Lorentz correction, and the cooling due to radiation. In spite of these limitations, the effects discussed would seem to be observable.Comment: 20 pages, 8 figure

Surrogate Markers for Time-Varying Treatments and Outcomes

BACKGROUND: A surrogate marker is a variable commonly used in clinical trials to guide treatment decisions when the outcome of ultimate interest is not available. A good surrogate marker is one where the treatment effect on the surrogate is a strong predictor of the effect of treatment on the outcome. We review the situation when there is one treatment delivered at baseline, one surrogate measured at one later time point, and one ultimate outcome of interest and discuss new issues arising when variables are time-varying. METHODS: Most of the literature on surrogate markers has only considered simple settings with one treatment, one surrogate, and one outcome of interest at a fixed time point. However, more complicated time-varying settings are common in practice. In this article, we describe the unique challenges in two settings, time-varying treatments and time-varying surrogates, while relating the ideas back to the causal-effects and causal-association paradigms. CONCLUSION: In addition to discussing and extending popular notions of surrogacy to time-varying settings, we give examples illustrating that one can be misled by not taking into account time-varying information about the surrogate or treatment. We hope this article has provided some motivation for future work on estimation and inference in such settings

A model for regulation by SynGAP-α1 of binding of synaptic proteins to PDZ-domain 'Slots' in the postsynaptic density

SynGAP is a Ras/Rap GTPase-activating protein (GAP) that is a major constituent of postsynaptic densities (PSDs) from mammalian forebrain. Its α1 isoform binds to all three PDZ (PSD-95, Discs-large, ZO-1) domains of PSD-95, the principal PSD scaffold, and can occupy as many as 15% of these PDZ domains. We present evidence that synGAP-α1 regulates the composition of the PSD by restricting binding to the PDZ domains of PSD-95. We show that phosphorylation by Ca^(2+)/calmodulin-dependent protein kinase II (CaMKII) and Polo-like kinase-2 (PLK2) decreases its affinity for the PDZ domains by several fold, which would free PDZ domains for occupancy by other proteins. Finally, we show that three critical postsynaptic signaling proteins that bind to the PDZ domains of PSD-95 are present in higher concentration in PSDs isolated from mice with a heterozygous deletion of synGAP

Studying changes in the practice of two teachers developing assessment for learning

This paper describes changes in the practice of two teachers, observed over an eighteen month period, who were participating in a study intended to support teachers in developing their use of assessment in support of learning. The design of the intervention allowed each teacher to choose for themselves which aspects of their practice to develop. Analysis of lesson observations, journal entries and interviews indicate that both teachers were keen to change their practice, but were concerned about the disruption to their established routines, and in particular about the potential for loss of control of their classes. Both teachers did effect significant changes in their classrooms, but these tended to be developments of existing preferred ways of working, rather than radical innovations. In conclusion, it is suggested that to be most effective, teacher professional development needs to be structured strongly enough to afford teacher growth, but flexible enough to allow different teachers to take their practice in different ways