Response mode and stochastic choice together explain preference reversals

Informed by Grether and Plott (1979) and Cox and Grether (1996), we implement various preference elicitation procedures over a parameter grid. First, we find a lower incidence of preference reversals for probability equivalents from the dual-to-selling version of Becker, Degroot, and Marschak (1964; BDM) than for certainty equivalents from traditional BDM—consistent with conjectures regarding response mode. Second, the Blavatskyy (2009, 2012) model of probabilistic choice can explain the incidence of preference reversals when using probability equivalents. Thus, between response mode (outside the Blavatskyy model) and stochastic choice (as per Blavatskyy), preference reversals in the original certainty equivalent case seem to be explained. We also present estimates for risk and stochasticity parameters; the former are not correlated across mechanisms, but the latter are. Finally, relatively more error-laden behavior (based on within-mechanism checks) can be associated with fewer reversals across mechanisms. The data make clear, empirically, the logical proposition that reducing reversals requires only a better “match” with binary choice, not necessarily rational behavior at any deeper level

The Effects of a Core Stabilization Training Program on the Performance of Functional Tasks in Firefighters

International Journal of Exercise Science 17(4): 602-610, 2024. The purpose of this study was to observe if core stabilization training plays a significant role in firefighter time-to-completion during a functional performance test. A within subjects study design was used in which subjects (n = 13, 84.6% male, 33.7 ± 7.4 years of age, 91.06 ± 13.29 kg, 25.79 ± 6.55 percent body fat, 8.96 ± 7.51 years of firefighting experience) completed two performance tests (pre and post core training), comprised of 7 firefighter-specific exercises performed while wearing a 22.68 kg weight vest to mimic typical firefighter equipment. Between testing sessions, subjects were prescribed specific core stabilization exercises to perform at least three days a week for a total of 4 weeks. Time-to-completion was significantly quicker between the first (300.89 ± 42.11s) and second (256.92 ± 34.31s) performance testing, on average by 43.8 seconds (p \u3c 0.001). Body mass index (p = 0.065) and rating of perceived exertion during testing (p = 0.084) did not significantly decrease across the course of the study. Adequate fitness is essential to firefighters’ job task performance. Data from this study suggests that regular core stabilization training may assist in optimizing the effectiveness, and potentially safety, of firefighters’ performance in high intensity functional skills

A role for the SHANK1 scaffold protein in experience-induced synaptic plasticity and memory consolidation

The processes by which the brain acquires, stores, and retrieves external information has been an extensively researched field in psychology. Findings from these studies have overwhelmingly suggested that plasticity of neuroanatomical networks across development and during various experiences provide a critical mechanism mediating learning. Specifically, numerous studies have suggested dendritic spine plasticity across development and during learning as a likely process for memory consolidation. During early postnatal development, dendritic spine density increases in numerous sensory cortices, reaching a peak in adolescence, followed by a subsequent reduction in dendritic spine density to adult levels. In the hippocampus, dendritic spine density steadily increases during postnatal development, and plateaus in adulthood. Similar to the plasticity observed across development, increases in dendritic spine density occur in the neocortex and hippocampus following various learning paradigms, suggesting synaptic remodeling. While the anatomical properties for these forms of plasticity are well investigated, the underlying molecular processes remain largely unknown. Interestingly, recent studies have strongly suggested a role for SHANK1 in normal synaptic development and plasticity. SHANK1 is a scaffolding protein that is concentrated to the postsynaptic density (PSD) of excitatory synapses and is involved in the binding of glutamate receptors to their active zones. Previous developmental studies have demonstrated that SHANK1 is initially localized in the cytoplasm of neurons followed by an increased dendritic spine expression during periods of postnatal dendritic spine proliferation. Likewise, SHANK1 expression is increased across postnatal development in purified postsynaptic fractions, further suggesting a role in developmental properties of dendritic spines. Interestingly, global SHANK1 knockout (SHANK1 -/-) mice have also been shown to exhibit a reduction in dendritic spine density and increased immature dendritic spine phenotype. Consistent with that observed in development, SHANK1 has been hypothesized to play an important role in learning-induced dendritic spine plasticity and cognition. SHANK1-/- mice exhibit marked impairments in contextual fear-conditioning and radial-arm-maze retention. Similarly, mice that overexpress SHANK1 exhibit impairments in both cued and contextual fear conditioning, further suggesting that appropriate SHANK1 regulation is crucial for normal cognition.Collectively, these studies strongly suggest a role for SHANK1 in developmental and learning-induced dendritic spine plasticity; however, a detailed examination of this has never been conducted. Furthermore, many of these studies genetically dysregulated SHANK1 from birth, thus a role for SHANK1 in normal adult learning-induced plasticity has not yet been examined. The studies in the present thesis further explored SHANK1 as an underlying mediator of dendritic spine plasticity in three specific aims. In Aim 1, a detailed examination of layer and cell-specific dendritic spine plasticity in S1 during distinct learning phases for WTEB was conducted. Findings from this study revealed no significant changes in dendritic spine density on layer III or layer V pyramidal cells at the specific time points examined across WTEB. In exploring these findings, we further discussed the implications of these findings, possible explanations as well as potential future studies to explore this research question. Aim 2 explored a role for SHANK1 expression during neuronal development, a well characterized period of dendritic spine plasticity. These studies demonstrated SHANK1 localization to neurons as well as astrocytes and microglia. Furthermore, this study also characterized cell-specific changes in SHANK1 expression during periods of developmental synaptic plasticity. Aim 3 expanded upon these findings to explore a role SHANK1 expression, during learning-induced neocortical dendritic spine plasticity and learning of WTEB. These studies demonstrated a transient increase in SHANK1 levels during periods of neocortical synaptic plasticity across WTEB. Collectively, these studies further support a role of SHANK1 in the organization and remodeling of synaptic networks during development and learning. In so doing these studies also provided additional insight into potential specific mechanisms underlying developmental and experience-induced synaptic remodeling, deepening our understanding of memory consolidation within specific learning networks

A Comparison of External Loads in Division III Men\u27s Lacrosse Between High Competition Matches and Low Competition Matches

Lacrosse is an open field sport with limited knowledge on the demands of gameplay at the Division III level. The purpose of this study was to investigate the external loads on Division III men’s lacrosse players during NCAA season games. Comparisons were made between the external loads placed on the athletes in top competition versus external loads placed on the athletes in low competition matches. Top competition matches were defined as matches against teams that qualified for the NCAA tournament whereas low competition matches included teams that did not meet top competition requirements. The dependent variables measured included total distance, work rate, intensity, 2D load, and 3D load. Defensive players were found to have significantly higher external load values for total distance (m; p=0.003), work rate (m/min; p=0.006 ), intensity (AU; p=0.071), 2D load (AU; p= 0.039 ) and 3D load (AU; p=0.022), while there were no significant differences (p\u3e0.05) for other positions between competition level. Competition level exerts a higher external load for defensive players, but not attack, midfield, or specialists (goalie, face-off, etc), which may indicate the need for specialized conditioning or active load management to deal with potential fatigue

Microscopic crystallographic analysis of dislocations in molecular crystals

Organic molecular crystals encompass a vast range of materials from pharmaceuticals to organic optoelectronics and proteins to waxes in biological and industrial settings. Crystal defects from grain boundaries to dislocations are known to play key roles in mechanisms of growth and also in the functional properties of molecular crystals. In contrast to the precise analysis of individual defects in metals, ceramics, and inorganic semiconductors enabled by electron microscopy, significantly greater ambiguity remains in the experimental determination of individual dislocation character and slip systems in molecular materials. In large part, nanoscale dislocation analysis in molecular crystals has been hindered by the severely constrained electron exposures required to avoid irreversibly degrading these crystals. Here, we present a low-dose, single-exposure approach enabling nanometre-resolved analysis of individual extended dislocations in molecular crystals. We demonstrate the approach for a range of crystal types to reveal dislocation character and operative slip systems unambiguously.Comment: Manuscript (14 pages, 4 figures) and Supplementary Material (32 pages, 19 figures) in a single PDF fil

Defining the current distribution of the imperiled Black-spotted Newt across south Texas, USA

The Black-spotted Newt (Notophthalmus meridionalis) is a chronically understudied salamander species, with many aspects of its natural history, ecology, and distribution poorly known. Previous studies using traditional methodologies have had limited success documenting N. meridionalis on the landscape, detecting individuals at 6% (7 of 114) and 1% (2 of 221) of sites surveyed. A novel environmental DNA (eDNA) assay was designed and implemented with the goals of assessing the current distribution of N. meridionalis across south Texas, USA, and better understanding the conditions for positive eDNA detections. We conducted eDNA sampling and traditional surveys at 80 sites throughout south Texas. Notophthalmus meridionalis was detected at 12 localities in total: four localities using eDNA surveys, four localities using traditional methods, and four localities with both methodologies. eDNA detections were obtained from five counties, including one where N. meridionalis has never been reported and another where N. meridionalis has not been observed since the 1930s. eDNA detections were obtained in all four seasons, generally following moderate to heavy rainfall events. Our results support the increased use of eDNA surveys to detect rare and cryptic amphibians and to better understand the current distribution of this imperiled species

A mitochondrial-focused genetic interaction map reveals a scaffold-like complex required for inner membrane organization in mitochondria.

To broadly explore mitochondrial structure and function as well as the communication of mitochondria with other cellular pathways, we constructed a quantitative, high-density genetic interaction map (the MITO-MAP) in Saccharomyces cerevisiae. The MITO-MAP provides a comprehensive view of mitochondrial function including insights into the activity of uncharacterized mitochondrial proteins and the functional connection between mitochondria and the ER. The MITO-MAP also reveals a large inner membrane-associated complex, which we term MitOS for mitochondrial organizing structure, comprised of Fcj1/Mitofilin, a conserved inner membrane protein, and five additional components. MitOS physically and functionally interacts with both outer and inner membrane components and localizes to extended structures that wrap around the inner membrane. We show that MitOS acts in concert with ATP synthase dimers to organize the inner membrane and promote normal mitochondrial morphology. We propose that MitOS acts as a conserved mitochondrial skeletal structure that differentiates regions of the inner membrane to establish the normal internal architecture of mitochondria

J/Psi Production from Electromagnetic Fragmentation in Z decay

The rate for $Z^{0}\to J/ \psi + \ell^{+}\ell^{-}$ is suprisingly large with about one event for every million $Z^{0}$ decays. The reason for this is that there is a fragmentation contribution that is not suppressed by a factor of $M^{2}_{\psi}/M^{2}_{Z}$. In the fragmentation limit $M_{Z}\to\infty$ with $E_{\psi}/M_{Z}$ fixed, the differential decay rate for $Z^{0}\to J/ \psi + \ell^{+}\ell^{-}$ factors into electromagnetic decay rates and universal fragmentation functions. The fragmentation functions for lepton fragmentation and photon fragmentation into $J/\psi$ are calculated to lowest order in $\alpha$. The fragmentation approximation to the rate is shown to match the full calculation for $E_{\psi}$ greater than about $3 M_{\psi}$.Comment: 16 pages and 8 figure