Structural concepts and experimental considerations for a versatile high-speed research airplane

Future aircraft may be hydrogen fueled and fly at hypersonic speeds. The resulting environments will require new structural concepts to satisfy performance goals. Large representative structures will have to be flight tested prior to commitment to a costly vehicle fleet. To perform flight tests, a versatile, economical, high-speed research airplane is defined. Results of this study including experimental considerations for a hypersonic research airplane are reported

Solving tile drainage problems by using model data

Our purpose in this bulletin is to report, to analyze, and to use in problem solving, extensive model data of tile drainage of land. The data were obtained with a glassbead-glycerol model (Grover et al., 1960; Grover and Kirkham, 1961) and inc1ude: (a) values of depths and of corresponding times of fall of the surface of saturation to these depths at various distances from the drain tubes and (b) values of the drain tube discharge rates. The zero reference time for the fall of the surface of saturation and also for the discharge rate is the instant at which the surface of saturation passes through the simulated soil surface from a ponded condition. Models were made of 109 different combinations of drain depth, drain spacing and soil stratification. For each of these 109 model conditions, the surfaces of saturation were photographed at about eight different depths through the transparent front face of the model. Photographs were read under a magnifying glass to obtain distances and times of fall. Times were obtained from a clock that was started at the zero reference time and photographed with the water tables

Slope monitoring at the Glan Ebbw Landslide, Blaina, South Wales: January to April 2016

This report describes survey work carried out at a landslide site in Blaina, West Side, South Wales between January and April 2016. The Terrestrial Laser Scan (LiDAR) and GPS survey of ground pins was undertaken and funded by the British Geological Survey (BGS). The aim was to provide Blaenau Gwent Council Environment Department with a survey baseline against which further ground movement can be assessed and data for research purposes

Characterisation and calibration of a large aperture (1.6 m) ka-band indoor passive millimetre wave security screening imager

A large 1.6 m aperture mechanically scanning quasi-optical millimetre wave imaging system designed for active use [1] has been investigated for its passive millimetre wave (PMMW) imaging capabilities. This raises new challenges for this imager, as the person / background contrast in indoor security scenarios at these frequencies is in the region of 6-7 K. The system is sensitive over 24 – 28 GHz and has a radiometric sensitivity measured at 6.5 K in a single frame, at a frame rate of 8.8 Hz. It was found that the focal plane receiver array radiated an excess noise ratio (ENR) of typically 9 dB. This radiation re-entered the focal plane array receivers after reflection from the imager optical components typically with a standard deviation of 17 K over the mechanical scan associated with a single image frame. Reflected from subjects in the field of view, it was typically 400 K from a 100 % reflective surface, and 40 K to 100 K from a human subject. This radiation, termed self-emission in this paper, is a feature of many PMMW imaging systems that use highgain electronic amplifiers in their receiving systems. The effectiveness in the use of a calibration mechanism to subtract self-emission reflected from the optical components and a large area quarter wave plate to minimising the amount of self-emission reflected back from subjects is demonstrated. The present system would benefit greatly from replacement amplifiers of larger bandwidth, lower self-emission and lower noise figure. It was also found that the millimetre wave emission from fluorescent room lighting entered the optics of the imager and modulated the received signals at 100 Hz. The mean level of emission was measured at 10 K with a 10 K modulation at 100 Hz for per mode for a 100 % reflecting surface in the room. The best solution to the problem of emission from fluorescent lights was to turn them off and use incandescent lighting

Progenitor cell dynamics in the newt telencephalon during homeostasis and neuronal regeneration

Acknowledgments: We would like to thank E. Andersson and U. Lendahl for providing reagents and for helpful discussions. This work was supported by grants from AFA Insurances, Cancerfonden, Swedish Research Council, and European Research Council to A.S. M.K. was supported by a HFSPO postdoc fellowship.Peer reviewedPublisher PD

Iron mobilization during lactation reduces oxygen stores in a diving mammal

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Shero, M. R., Kirkham, A. L., Costa, D. P., & Burns, J. M. Iron mobilization during lactation reduces oxygen stores in a diving mammal. Nature Communications, 13(1), (2022): 4322, https://doi.org/10.1038/s41467-022-31863-7.The profound impacts that maternal provisioning of finite energy resources has on offspring survival have been extensively studied across mammals. This study shows that in addition to calories, high hemoprotein concentrations in diving mammals necessitates exceptional female-to-pup iron transfer. Numerous indices of iron mobilization (ferritin, serum iron, total-iron-binding-capacity, transferrin saturation) were significantly elevated during lactation in adult female Weddell seals (Leptonychotes weddellii), but not in skip-breeders. Iron was mobilized from endogenous stores for incorporation into the Weddell seal’s milk at concentrations up to 100× higher than terrestrial mammals. Such high rates of iron offload to offspring drew from the female’s own heme stores and led to compromised physiologic dive capacities (hemoglobin, myoglobin, and total body oxygen stores) after weaning their pups, which was further reflected in shorter dive durations. We demonstrate that lactational iron transfer shapes physiologic dive thresholds, identifying a cost of reproduction to a marine mammal.This research was conducted with support from NSF ANT-0838892 to DPC; ANT-0838937 and ANT-1246463 to JMB (which also supported ALK and MRS); and The Investment in Science Fund at WHOI to MRS

Tissue engineering a fetal membrane

The aim of this study was to construct an artificial fetal membrane (FM) by combination of human amniotic epithelial stem cells (hAESCs) and a mechanically enhanced collagen scaffold containing encapsulated human amniotic stromal fibroblasts (hASFs). Such a tissue-engineered FM may have the potential to plug structural defects in the amniotic sac after antenatal interventions, or to prevent preterm premature rupture of the FM. The hAESCs and hASFs were isolated from human fetal amniotic membrane (AM). Magnetic cell sorting was used to enrich the hAESCs by positive ATP-binding cassette G2 selection. We investigated the use of a laminin/fibronectin (1:1)-coated compressed collagen gel as a novel scaffold to support the growth of hAESCs. A type I collagen gel was dehydrated to form a material mimicking the mechanical properties and ultra-structure of human AM. hAESCs successfully adhered to and formed a monolayer upon the biomimetic collagen scaffold. The resulting artificial membrane shared a high degree of similarity in cell morphology, protein expression profiles, and structure to normal fetal AM. This study provides the first line of evidence that a compacted collagen gel containing hASFs could adequately support hAESCs adhesion and differentiation to a degree that is comparable to the normal human fetal AM in terms of structure and maintenance of cell phenotype