Physicochemical effects on the abundance and distribution of larval fishes in the Atchafalaya River Basin, Louisiana

The Atchafalaya River Basin (ARB) experiences overbank inundations as springtime temperatures warm that create conditions favorable for bacterial respiration, which results in hypoxic conditions (dissolved oxygen [DO] ≤ 2.0 mg/L). Previous ARB research has shown that pelagic larval fish populations are impacted by hypoxic conditions, and that larvae may use macrophyte beds (e.g., hydrilla Hydrilla verticillata) as DO refugia. I examined the relationship between physicochemistry and the distribution and abundance or larval fishes associated with ARB macrophyte beds during 2001-2002. Larval fishes were collected with light traps at two normoxic and hypoxic sites, and at each site, surface and subsurface traps were placed in open channels, hydrilla beds, and the interface between the channel and macrophyte beds (border). Of the 1,718 larval fishes representing 10 families that were collected, centrarchids Lepomis spp. (45.5%) and catostomids Ictiobus spp. (25.7%) dominated the 2001 assemblage, whereas percids Etheostoma spp. (29.1%) and centrarchids (17.8%) were most abundant in 2002. River stages between years were different from each other (P \u3c 0.001), and from the 42-year stage average (P \u3c 0.001). Between-year differences in flood pulse timing and duration resulted in higher pH, temperature, and DO levels, and 2.5 times more larval fishes in 2001. Overall, larval fish abundances under hypoxic conditions were severely reduced during both years. Under normoxic conditions, larval fishes were collected from all habitats, but were typically in higher abundance in nearshore areas regardless of cover conditions (hydrilla vs. no cover). Larvae that could withstand hypoxic conditions (centrarchids, clupeids, cyprinids, and percids) were typically found in nearshore areas associated with hydrilla beds. Because of the increased abundance of predatory invertebrates in these areas, the use of hydrilla beds by fish larvae as oxygen refugia may provide optimal physiochemical conditions at an increased predation risk. Man-made alterations in the ARB have changed circulation patterns on the inundated floodplain, which contribute to seasonally widespread hypoxic conditions and reductions in larval fish abundance. Thus, any management plan that increases the historic connection between the mainstem Atchafalaya River and the floodplain, and improves floodplain circulation would benefit larval fish production in the ARB

Enabling Real-Time Ultrasound Imaging of Soft Tissue Mechanical Properties by Simplification of the Shear Wave Motion Equation

Ultrasound based shear wave elastography (SWE) is a technique used for non-invasive characterization and imaging of soft tissue mechanical properties. Robust estimation of shear wave propagation speed is essential for imaging of soft tissue mechanical properties. In this study we propose to estimate shear wave speed by inversion of the firstorder wave equation following directional filtering. This approach relies on estimation of first-order derivatives which allows for accurate estimations using smaller smoothing filters than when estimating second-order derivatives. The performance was compared to three current methods used to estimate shear wave propagation speed: direct inversion of the wave equation (DIWE), time-to-peak (TTP) and crosscorrelation (CC). The shear wave speed of three homogeneous phantoms of different elastic moduli (gelatin by weight of 5%, 7%, and 9%) were measured with each method. The proposed method was shown to produce shear speed estimates comparable to the conventional methods (standard deviation of measurements being 0.13 m/s, 0.05 m/s, and 0.12 m/s), but with simpler processing and usually less time (by a factor of 1, 13, and 20 for DIWE, CC, and TTP respectively). The proposed method was able to produce a 2-D speed estimate from a single direction of wave propagation in about four seconds using an off-the-shelf PC, showing the feasibility of performing real-time or near real-time elasticity imaging with dedicated hardware

Effects of Local Blood Flow on Muscle Stiffness

Muscle injuries, in the form of strains or even tears, affect millions of people each year through undue tension on muscles during everyday activities, work tasks, or physical activity including sports or working out. These injuries can take from a few weeks to even months to heal, with patients having to deal with inflammation, swelling, and pain throughout the healing process. Scar tissue also forms when the muscle is injured, which regenerates throughout the healing process, but never fully recovers to its state prior to injury. This scar tissue is thought to make the muscle more prone to subsequent injury, making it important to avoid muscle injuries to begin with so as to not lose overall strength and range of motion. Although there are currently certain activities identified to increase the probability of muscle injury, there is limited evidence as to what physiological components may make an individual more susceptible to injury. Therefore, the purpose of this study is to look at the association between two measures; blood flow velocity through muscle using Doppler ultrasound and the muscle\u27s stiffness, or Young\u27s modulus, using ultrasound elastography. A notable correlation between the two factors could allow clinicians to know if patients have a predisposition to muscle injury due to their rate of blood flow

A termite from the Late Oligocene of northern Ethiopia

This is the publisher's version, also available electronically from http://www.app.pan.pl/article/item/app20110198.htmlTermites of the family Stolotermitidae are a relict lineage of primitive Isoptera. The fossil record of Stolotermitidae is exceptionally poor, with only two Miocene (Neogene) species documented to date. Herein, a new genus and species of Paleogene termites is described and figured from the Late Oligocene (28–27 Ma, Early Chattian) of northwestern Ethiopia (Amhara Region, Chilga Woreda). Chilgatermes diamatensis gen. et sp. nov., is most similar to genera of the Stolotermitidae, Archotermopsidae, and Termopsidae but can be distinguished on the basis of forewing venational details. The genus is tentatively placed in the Stolotermitidae: Porotermitinae. Chilgatermes diamatensis is the first fossil termite from Ethiopia and, indeed, the first from the entire African continent

The Effect of Wireless Symmetries on Cryptoanalysis

The essential unification of thin clients and suffix trees is an unfortunate quandary. In fact, few researchers would disagree with the understanding of vacuum tubes, which embodies the structured principles of cy- berinformatics. Here, we construct new atomic theory (Museum), disproving that randomized algorithms and public-private key pairs are mostly incompatible

Deepwater Horizon oil spill exposures and nonfatal myocardial infarction in the GuLF STUDY.

BACKGROUND: Workers involved in the response and clean-up of the 2010 Deepwater Horizon oil spill faced possible exposures to crude oil, burning oil, dispersants and other pollutants in addition to physical and emotional stress. These exposures may have increased risk of myocardial infarction (MI) among oil spill workers. METHODS: Gulf Long-term Follow-up (GuLF) STUDY participants comprise individuals who either participated in the Deepwater Horizon response efforts or registered for safety training but were not hired. Oil spill-related exposures were assessed during enrollment interviews conducted in 2011-2013. We estimated risk ratios (RR) and 95% confidence intervals for the associations of clean-up work characteristics with self-reported nonfatal MI up to three years post-spill. RESULTS: Among 31,109 participants without history of MI prior to the spill, 77% worked on the oil spill. There were 192 self-reported MI during the study period; 151 among workers. Among the full cohort, working on the oil spill clean-up (vs not working on the clean-up) and living in proximity to the oil spill (vs further away) were suggestively associated with a possible increased risk of nonfatal MI [RR: 1.22 (0.86, 1.73) and 1.15 (0.82, 1.60), respectively]. Among oil spill workers, working for > 180 days was associated with MI [RR for > 180 days (vs 1-30 days): 2.05 (1.05, 4.01)], as was stopping working due to heat [RR: 1.99 (1.43, 2.78)]. There were suggestive associations of maximum total hydrocarbon exposure ≥3.00 ppm (vs  180 days and stopping work due to heat increased risk of nonfatal MI. Future research should evaluate whether the observed associations are related to specific chemical exposures or other stressors associated with the spill

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development and Performance Analysis

The Space Launch System (SLS) base heating test is broken down into two test programs: (1) Pathfinder and (2) Main Test. The Pathfinder Test Program focuses on the design, development, hot-fire test and performance analyses of the 2% sub-scale SLS core-stage and booster element propulsion systems. The core-stage propulsion system is composed of four gaseous oxygen/hydrogen RS-25D model engines and the booster element is composed of two aluminum-based model solid rocket motors (SRMs). The first section of the paper discusses the motivation and test facility specifications for the test program. The second section briefly investigates the internal flow path of the design. The third section briefly shows the performance of the model RS-25D engines and SRMs for the conducted short duration hot-fire tests. Good agreement is observed based on design prediction analysis and test data. This program is a challenging research and development effort that has not been attempted in 40+ years for a NASA vehicle

Growth and characterization of α\alpha-Sn thin films on In- and Sb-rich reconstructions of InSb(001)

$\alpha$-Sn thin films can exhibit a variety of topologically non-trivial phases. Both studying the transitions between these phases and making use of these phases in eventual applications requires good control over the electronic and structural quality of $\alpha$-Sn thin films. $\alpha$-Sn growth on InSb often results in out-diffusion of indium, a p-type dopant. By growing $\alpha$-Sn via molecular beam epitaxy on the Sb-rich c(4$\times$4) surface reconstruction of InSb(001) rather than the In-rich c(8$\times$2), we demonstrate a route to substantially decrease and minimize this indium incorporation. The reduction in indium concentration allows for the study of the surface and bulk Dirac nodes in $\alpha$-Sn via angle-resolved photoelectron spectroscopy without the common approaches of bulk doping or surface dosing, simplifying topological phase identification. The lack of indium incorporation is verified in angle-resolved and -integrated ultraviolet photoelectron spectroscopy as well as in clear changes in the Hall response

First Principles Assessment of CdTe as a Tunnel Barrier at the α\mathbf{\alpha}-Sn/InSb Interface

Majorana zero modes, with prospective applications in topological quantum computing, are expected to arise in superconductor/semiconductor interfaces, such as $\beta$-Sn and InSb. However, proximity to the superconductor may also adversely affect the semiconductor's local properties. A tunnel barrier inserted at the interface could resolve this issue. We assess the wide band gap semiconductor, CdTe, as a candidate material to mediate the coupling at the lattice-matched interface between $\alpha$-Sn and InSb. To this end, we use density functional theory (DFT) with Hubbard U corrections, whose values are machine-learned via Bayesian optimization (BO) [npj Computational Materials 6, 180 (2020)]. The results of DFT+U(BO) are validated against angle resolved photoemission spectroscopy (ARPES) experiments for $\alpha$-Sn and CdTe. For CdTe, the z-unfolding method [Advanced Quantum Technologies, 5, 2100033 (2022)] is used to resolve the contributions of different $k_z$ values to the ARPES. We then study the band offsets and the penetration depth of metal-induced gap states (MIGS) in bilayer interfaces of InSb/$\alpha$-Sn, InSb/CdTe, and CdTe/$\alpha$-Sn, as well as in tri-layer interfaces of InSb/CdTe/$\alpha$-Sn with increasing thickness of CdTe. We find that 16 atomic layers (3.5 nm) of CdTe can serve as a tunnel barrier, effectively shielding the InSb from MIGS from the $\alpha$-Sn. This may guide the choice of dimensions of the CdTe barrier to mediate the coupling in semiconductor-superconductor devices in future Majorana zero modes experiments

Deepwater Horizon oil spill exposures and nonfatal myocardial infarction in the GuLF STUDY

Abstract Background Workers involved in the response and clean-up of the 2010 Deepwater Horizon oil spill faced possible exposures to crude oil, burning oil, dispersants and other pollutants in addition to physical and emotional stress. These exposures may have increased risk of myocardial infarction (MI) among oil spill workers. Methods Gulf Long-term Follow-up (GuLF) STUDY participants comprise individuals who either participated in the Deepwater Horizon response efforts or registered for safety training but were not hired. Oil spill-related exposures were assessed during enrollment interviews conducted in 2011–2013. We estimated risk ratios (RR) and 95% confidence intervals for the associations of clean-up work characteristics with self-reported nonfatal MI up to three years post-spill. Results Among 31,109 participants without history of MI prior to the spill, 77% worked on the oil spill. There were 192 self-reported MI during the study period; 151 among workers. Among the full cohort, working on the oil spill clean-up (vs not working on the clean-up) and living in proximity to the oil spill (vs further away) were suggestively associated with a possible increased risk of nonfatal MI [RR: 1.22 (0.86, 1.73) and 1.15 (0.82, 1.60), respectively]. Among oil spill workers, working for > 180 days was associated with MI [RR for > 180 days (vs 1–30 days): 2.05 (1.05, 4.01)], as was stopping working due to heat [RR: 1.99 (1.43, 2.78)]. There were suggestive associations of maximum total hydrocarbon exposure ≥3.00 ppm (vs < 0.30 ppm) [RR: 1.69 (0.90, 3.19)] and working on decontaminating oiled equipment (vs administrative support) [1.72 (0.96, 3.09)] with nonfatal MI. Conclusion This is the first study to assess the associations between oil spill exposures and MI. Results suggest that working on the spill for > 180 days and stopping work due to heat increased risk of nonfatal MI. Future research should evaluate whether the observed associations are related to specific chemical exposures or other stressors associated with the spill