Investigating Saxitoxin Resistance in Softshell Clams (Mya arenaria): Patterns of Inheritance and Improvements on Methodology for Tracking and Identification

Attempts to characterize and study the population dynamics of the softshell clam Mya arenaria in relation to a mutation which confers resistance to paralytic shellfish toxins are complicated by a lack of non-lethal genotyping techniques, reliable tagging methods and an understanding of the inheritance patterns of the marker. Presented here, is a straightforward and non-lethal technique for clam genotyping, a new method for the long term tagging of clams, and the offspring genotype frequencies from a number of pair matings between clams of known genotype. Hemolymph extracted from M. arenaria was used directly in a polymerase chain reaction (PCR) to successfully amplify a DNA fragment suitable for sequencing. Tested M. arenaria showed 100% (n=10) survival after a period of four weeks. In a separate experiment, passive integrated transponder (PIT) tags were inserted between the mantle and shells of 72 clams that were monitored for tag retention and survival. Among all PIT tagged clams, there was 100% survival and 92 % tag retention. These methods provide a mechanism by which softshell clams can be genotyped and individually monitored, during field experiments. Sixteen pair matings were conducted with adult M. arenaria of known genotype. Using polymerase chain reaction (PCR), the domain II (DII) pore region of the voltage-gated Na+ channel a-subunit, in which the mutation is found, was identified in a total of 344 larvae from these crosses. The data support the hypothesis that the mutant allele can be inherited from either sex and that there are no barriers to fertilization between gametes of different genotypes. Of the ten cross offspring genotype frequencies analyzed using goodness-of-fit tests, seven adhere to Mendelian expectations for inheritance, while three significantly deviated from expected ratios. These deviations are assumed not to be an actual representation of the sampled larval populations, but rather due to a combination of small larval sample size and a conservatively high significance level. This study demonstrates that the single nucleotide polymorphism in question is most likely inherited in a Mendelian fashion

Dairy grazing: heifer development

Original authors: Tony R. Rickard and Stacey A. Hamilton (University of Missouri). Revised 2022 Scott Poock and Stacey Hamilton.stats082022upload"Dairy heifers are the foundation of any dairy enterprise and directly affect future profitability. Because replacement heifers represent a negative cash flow, this aspect of the dairy operation is often neglected. Unfortunately, this neglect often costs producers large amounts of money. The goals of a heifer program should be to achieve the proper size and weight for the particular breed being raised and to calve by 22 to 24 months of age. Missouri data indicate an average age at first calving of 27 to 28 months. The lost net income per heifer is estimated to be at least $1.50 per day for each day over 24 months of age until freshening."--Page 1.Stacey A. Hamilton (Dairy Specialist, Animal Science Department), Scott E. Poock (State Dairy Extension Veterinarian

Photon-number-resolution with sub-30-ps timing using multi-element superconducting nanowire single photon detectors

A photon-number-resolving detector based on a four-element superconducting nanowire single photon detector is demonstrated to have sub-30-ps resolution in measuring the arrival time of individual photons. This detector can be used to characterize the photon statistics of non-pulsed light sources and to mitigate dead-time effects in high-speed photon counting applications. Furthermore, a 25% system detection efficiency at 1550 nm was demonstrated, making the detector useful for both low-flux source characterization and high-speed photon-counting and quantum communication applications. The design, fabrication and testing of this detector are described, and a comparison between the measured and theoretical performance is presented.Comment: 13 pages, 5 figure

Diagnostic Imaging in the Medical Support of the Future Missions to the Moon

This viewgraph presentation is a course that reviews the diagnostic imaging techniques available for medical support on the future moon missions. The educational objectives of the course are to: 1) Update the audience on the curreultrasound imaging in space flight; 2) Discuss the unique aspects of conducting ultrasound imaging on ISS, interplanetary transit, ultrasound imaging on ISS, interplanetary transit, and lunar surface operations; and 3) Review preliminary data obtained in simulations of medical imaging in lunar surface operations

The Ricci flow on noncommutative two-tori

In this paper we construct a version of Ricci flow for noncommutative 2-tori, based on a spectral formulation in terms of the eigenvalues and eigenfunction of the Laplacian and recent results on the Gauss-Bonnet theorem for noncommutative tori.Comment: 18 pages, LaTe

Dose-Response Evaluation of Braslet-M Occlusion Cuffs

Introduction: Braslet-M is a set of special elasticized thigh cuffs used by the Russian space agency to reduce the effects of the head-ward fluid shift during early adaptation to microgravity by sequestering fluid in the lower extremities. Currently, no imaging modalities are used in the calibration of the device, and the pressure required to produce a predictable physiological response is unknown. This investigation intends to relate the pressure exerted by the cuffs to the extent of fluid redistribution and commensurate physiological effects. Materials and Methods: Ten healthy subjects with standardized fluid intake participated in the study. Data collection included femoral and internal jugular vein imaging in two orthogonal planes, pulsed Doppler of cervical and femoral vessels and middle cerebral artery, optic nerve imaging, and echocardiography. Braslet-M cuff pressure was monitored at the skin interface using pre-calibrated pressure sensors. Using 6 and 30 head-down tilt in two separate sessions, the effect of Braslet-M was assessed while incrementally tightening the cuffs. Cuffs were then simultaneously released to document the resulting hemodynamic change. Results: Preliminary analysis shows correlation between physical pressure exerted by the Braslet-M device and several parameters such as jugular and femoral vein cross-sections, resistivity of the lower extremity vascular bed, and others. A number of parameters reflect blood redistribution and will be used to determine the therapeutic range of the device and to prevent unsafe application. Conclusion: Braslet-M exerts a physical effect that can be measured and correlated with many changes in central and peripheral hemodynamics. Analysis of the full data set will be required to make definitive recommendations regarding the range of safe therapeutic application. Objective data and subjective responses suggest that a safer and equally effective use of Braslet can be achieved when compared with the current non-imaging calibration techniques

Computational/Experimental Aeroheating Predictions for X-33

Laminar and turbulent heating-rate calculations from an "engineering" code and laminar calculations from a "benchmark" Navier-Stokes code are compared with experimental wind-tunnel data obtained on several candidate configurations for the X-33 Phase 2 flight vehicle. The experimental data were obtained at a Mach number of 6 and a freestream Reynolds number ranging from 1 to 8 x 10(exp 6)/ft. Comparisons are presented along the windward symmetry plane and in a circumferential direction around the body at several axial stations at angles of attack from 20 to 40 deg. The experimental results include both laminar and turbulent flow. For the highest angle of attack some of the measured heating data exhibited a "non-laminar" behavior which caused the heating to increase above the laminar level long before "classical" transition to turbulent flow was observed. This trend was not observed at the lower angles of attack. When the flow was laminar, both codes predicted the heating along the windward symmetry plane reasonably well but under-predicted the heating in the chine region. When the flow was turbulent the LATCH code accurately predicted the measured heating rates. Both codes were used to calculate heating rates over the X-33 vehicle at the peak heating point on the design trajectory and they were found to be in very good agreement over most of the vehicle windward surface

Flip the Clinic: A Digital Health Approach to Youth Mental Health Service Delivery During the COVID-19 Pandemic and Beyond.

The demand for mental health services is projected to rapidly increase as a direct and indirect result of the COVID-19 pandemic. Given that young people are disproportionately disadvantaged by mental illness and will face further challenges related to the COVID-19 pandemic, it is crucial to deliver appropriate mental health care to young people as early as possible. Integrating digital health solutions into mental health service delivery pathways has the potential to greatly increase efficiencies, enabling the provision of "right care, first time." We propose an innovative digital health solution for demand management intended for use by primary youth mental health services, comprised of (1) a youth mental health model of care (ie, the Brain and Mind Centre Youth Model) and (2) a health information technology specifically designed to deliver this model of care (eg, the InnoWell Platform). We also propose an operational protocol of how this solution could be applied to primary youth mental health service delivery processes. By "flipping" the conventional service delivery models of majority in-clinic and minority web-delivered care to a model where web-delivered care is the default, this digital health solution offers a scalable way of delivering quality youth mental health care both in response to public health crises (such as the COVID-19 pandemic) and on an ongoing basis in the future

Hypersonic Boundary-Layer Transition for X-33 Phase 2 Vehicle

A status review of the experimental and computational work performed to support the X-33 program in the area of hypersonic boundary-layer transition is presented. Global transition fronts are visualized using thermographic phosphor measurements. Results are used to derive transition correlations for "smooth body" and discrete roughness data and a computational tool is developed to predict transition onset for X-33 using these results. The X-33 thermal protection system appears to be conservatively designed for transition effects based on these studies. Additional study is needed to address concerns related to surface waviness. A discussion of future test plans is included

Entanglements of North Atlantic right whales increase as their distribution shifts in response to climate change: The need for a new management paradigm [poster]

Presented at 2019: World Marine Mammal Science Conference, Barcelona, Spain, December 9-12, 2019.Detection rate of severely injured or entangled NARWs began to increase around 2004 - 2007.We thank the North Atlantic Right Whale Consortium for data curation and dissemination, and the Atlantic Large Whale Disentanglement Network for entanglement sighting information