Condition Relative to Phenotype for Bass Populations in Southern Arkansas Lakes

Southern Arkansas reservoir largemouth bass populations (Micropterus salmoides) are often supplemented with stocks of Florida bass (M. floridanus) in an attempt to boost the frequency of hybrid and trophy bass. Stocking rates of Florida bass among these lakes are highly variable. We determined bass phenotype composition among 12 lake populations based upon stocking protocols: exclusively Florida bass, primarily Florida bass, mixed stocking protocol and primarily largemouth bass. We also compared condition among phenotypes (n =2,100) to test for hybrid or phenotype vigor. Mean relative weight of bass for most lakes but SWEPCO Lake (mean Wr = 72) were ≥ 90. Phenotype frequencies were inconsistent with FB stocking histories. No lake population was comprised only with pure Florida bass despite four of the lakes being stocked solely with this bass species. Numbers of F1 hybrid bass were low for all lake samples. Relative weight among phenotypes was also inconsistent among lake samples, allowing no conclusions to be made regarding relative weight and hybrid vigor or phenotype. Further testing increasing both the number of lake samples and sample size within lakes may provide insight into these questions of stocking effectiveness of Florida bass and hybrid or phenotype vigor

Occurrence and Reproduction of the Alabama Shad, Alosa alabamae Jordan and Evermann, in the Ouachita River System of Arkansas

The anadromous Alabama shad, Alosa alabamae, has drastically declined in abundance in recent decades throughout its historic range and has previously been reported in Arkansas from only five localities. Three of those locality records are pre- 1900. Sampling by seine in the Ouachita River drainage system of southern Arkansas in July and August of 1997 and 1998 produced more than 300 juvenile A. alabamae from two localities on the Little Missouri River and four localities on the Ouachita River. One record of an adult Alabama shad, taken on 4 April1997 by an angler below Remmel Dam on the Ouachita River, was also documented. Adults apparently ascended the Ouachita River and spawned successfully in 1997 and 1998 despite the construction of four locks and dams on that river in Louisiana and Arkansas in the 1980s. The Ouachita River drainage and a few streams in east-central Missouri are currently the only known spawning areas for A. alabamae in noncoastal regions of the entire Mississippi River basin. Continued survival of the Alabama shad in Arkansas depends on protecting critical spawning and nursery habitats in the Ouachita River system from deleterious alteration and on preserving that migratory species\u27 access to those habitats

Solar cell efficiency enhancement via light trapping in printable resonant dielectric nanosphere arrays

Resonant dielectric structures are a promising platform for addressing the key challenge of light trapping in thin-film solar cells. We experimentally and theoretically demonstrate efficiency enhancements in solar cells from dielectric nanosphere arrays. Two distinct amorphous silicon photovoltaic architectures were improved using this versatile light-trapping platform. In one structure, the colloidal monolayer couples light into the absorber in the near-field acting as a photonic crystal light-trapping element. In the other, it acts in the far-field as a graded index antireflection coating to further improve a cell which already included a state-of-the-art random light-trapping texture to achieve a conversion efficiency over 11%. For the near-field flat cell architecture, we directly fabricated the colloidal monolayer on the device through Langmuir–Blodgett deposition in a scalable process that does not degrade the active material. In addition, we present a novel transfer printing method, which utilizes chemical crosslinking of an optically thin adhesion layer to tether sphere arrays to the device surface. The minimally invasive processing conditions of this transfer method enable the application to a wide range of solar cells and other optoelectronic devices. False-color SEM image of an amorphous silicon solar cell with resonant spheres on top

Measurement of Contractile Stress Generated by Cultured Rat Muscle on Silicon Cantilevers for Toxin Detection and Muscle Performance Enhancement

Background: To date, biological components have been incorporated into MEMS devices to create cell-based sensors and assays, motors and actuators, and pumps. Bio-MEMS technologies present a unique opportunity to study fundamental biological processes at a level unrealized with previous methods. The capability to miniaturize analytical systems enables researchers to perform multiple experiments in parallel and with a high degree of control over experimental variables for high-content screening applications.Methodology/Principal Findings: We have demonstrated a biological microelectromechanical system (BioMEMS) based on silicon cantilevers and an AFM detection system for studying the physiology and kinetics of myotubes derived from embryonic rat skeletal muscle. It was shown that it is possible to interrogate and observe muscle behavior in real time, as well as selectively stimulate the contraction of myotubes with the device. Stress generation of the tissue was estimated using a modification of Stoney's equation. Calculated stress values were in excellent agreement with previously published results for cultured myotubes, but not adult skeletal muscle. Other parameters such as time to peak tension (TPT), the time to half relaxation (KRT) were compared to the literature. It was observed that the myotubes grown on the BioMEMS device, while generating stress magnitudes comparable to those previously published, exhibited slower TPT and KRT values. However, growth in an enhanced media increased these values. From these data it was concluded that the myotubes cultured on the cantilevers were of an embryonic phenotype. The system was also shown to be responsive to the application of a toxin, veratridine.Conclusions/Significance: The device demonstrated here will provide a useful foundation for studying various aspects of muscle physiology and behavior in a controlled high-throughput manner as well as be useful for biosensor and drug discovery applications

De Novo Mutations in SLC1A2 and CACNA1A Are Important Causes of Epileptic Encephalopathies

Epileptic encephalopathies (EEs) are the most clinically important group of severe early-onset epilepsies. Next-generation sequencing has highlighted the crucial contribution of de novo mutations to the genetic architecture of EEs as well as to their underlying genetic heterogeneity. Our previous whole-exome sequencing study of 264 parent-child trios revealed more than 290 candidate genes in which only a single individual had a de novo variant. We sought to identify additional pathogenic variants in a subset (n = 27) of these genes via targeted sequencing in an unsolved cohort of 531 individuals with a diverse range of EEs. We report 17 individuals with pathogenic variants in seven of the 27 genes, defining a genetic etiology in 3.2% of this unsolved cohort. Our results provide definitive evidence that de novo mutations in SLC1A2 and CACNA1A cause specific EEs and expand the compendium of clinically relevant genotypes for GABRB3. We also identified EEs caused by genetic variants in ALG13, DNM1, and GNAO1 and report a mutation in IQSEC2. Notably, recurrent mutations accounted for 7/17 of the pathogenic variants identified. As a result of high-depth coverage, parental mosaicism was identified in two out of 14 cases tested with mutant allelic fractions of 5%–6% in the unaffected parents, carrying significant reproductive counseling implications. These results confirm that dysregulation in diverse cellular neuronal pathways causes EEs, and they will inform the diagnosis and management of individuals with these devastating disorders

Multi-messenger searches via IceCube’s high-energy neutrinos and gravitational-wave detections of LIGO/Virgo

We summarize initial results for high-energy neutrino counterpart searches coinciding with gravitational-wave events in LIGO/Virgo\u27s GWTC-2 catalog using IceCube\u27s neutrino triggers. We did not find any statistically significant high-energy neutrino counterpart and derived upper limits on the time-integrated neutrino emission on Earth as well as the isotropic equivalent energy emitted in high-energy neutrinos for each event