DBI Realizations of the Pseudo-Conformal Universe and Galilean Genesis Scenarios

The pseudo-conformal universe is an alternative to inflation in which the early universe is described by a conformal field theory on approximately flat space-time. The fields develop time-dependent expectation values, spontaneously breaking the conformal symmetries to a de Sitter subalgebra, and fields of conformal weight zero acquire a scale invariant spectrum of perturbations. In this paper, we show that the pseudo-conformal scenario can be naturally realized within theories that would ordinarily be of interest for DBI inflation, such as the world-volume theory of a probe brane in an AdS bulk space-time. In this approach, the weight zero spectator field can be associated with a geometric flat direction in the bulk, and its scale invariance is protected by a shift symmetry.Comment: 34 page

The Use of Plasma Urea as an Indicator of Protein Status in Growing-Finishing Pigs

An experiment is being conducted on commercial swine operations to determine if plasma urea concentration can be used as an indicator of protein status in growing-finishing pigs. Swine producers in Eastern Nebraska are being selected to participate in this on-farm study. The experiment includes the completion of a 30-question survey and an on-farm visit for the collection of blood and feed samples. The survey includes questions about genetics, nutrition, housing and health. Preliminary results suggest that crude protein is overfed in most finishing diets. Gilts consistently have lower plasma urea concentrations than barrows when gilts and barrows are fed the same diet during the finishing growth period. This confirms the concept that gilts utilize protein more efficiently for lean growth. These results suggest that within an individual swine operation, plasma urea is a useful indicator of protein status in growing-finishing pigs

Dietary Amino Acid Utilization for Body Protein Deposition — Current and Future Research

In modern pork production it is important to maximize the animal’s potential for daily lean gain by increasing the body protein deposition with as little wastage of the ingested amino acids as possible. Therefore, it is important to maximize the efficiency with which dietary amino acids are used for protein deposition or lean gain. This efficiency is measured by using nitrogen balance studies or comparative slaughter procedures. Supplementing swine diets with crystalline amino acids and replacing part of the dietary protein can reduce diet cost and will also reduce the amount of nitrogen excreted in manure. However, it has been demonstrated that the efficiency of utilization of crystalline amino acids may be lower than that of amino acids bound in protein. Although the reasons for this are unclear, it may be associated with the frequency of feeding and differences in the rate of absorption between the two sources of amino acids. Research in progress is designed to investigate the efficiency with which crystalline lysine is utilized for protein deposition in nursery pigs. This research will obtain additional information about the relative utilization of crystalline and protein-bound amino acids

Single crystals of metal solid solutions

The following definitions were sought in the research on single crystals of metal solid solutions: (1) the influence of convection and/or gravity present during crystallization on the substructure of a metal solid solution; (2) the influence of a magnetic field applied during crystallization on the substructure of a metal solid solution; and (3) requirements for a space flight experiment to verify the results. Growth conditions for the selected silver-zinc alloy system are described, along with pertinent technical and experimental details of the project

Protective actions of des-acylated ghrelin on brain injury and blood-brain barrier disruption after stroke in mice

The major ghrelin forms, acylated ghrelin and des-acylated ghrelin, are novel gastrointestinal hormones. Moreover, emerging evidence indicates that these peptides may have other functions including neuro- and vaso-protection. Here, we investigated whether post-stroke treatment with acylated ghrelin or des-acylated ghrelin could improve functional and histological endpoints of stroke outcome in mice after transient middle cerebral artery occlusion (tMCAo). We found that des-acylated ghrelin (1 mg/kg) improved neurological and functional performance, reduced infarct and swelling, and decreased apoptosis. In addition, it reduced blood-brain barrier (BBB) disruption in vivo and attenuated the hyper-permeability of mouse cerebral microvascular endothelial cells after oxygen glucose deprivation and reoxygenation (OGD + RO). By contrast, acylated ghrelin (1 mg/kg or 5 mg/kg) had no significant effect on these endpoints of stroke outcome. Next we found that des-acylated ghrelin's vasoprotective actions were associated with increased expression of tight junction proteins (occludin and claudin-5), and decreased cell death. Moreover, it attenuated superoxide production, Nox activity and expression of 3-nitrotyrosine. Collectively, these results demonstrate that post-stroke treatment with des-acylated ghrelin, but not acylated ghrelin, protects against ischaemia/reperfusion-induced brain injury and swelling, and BBB disruption, by reducing oxidative and/or nitrosative damage

Accuracy Assessment of the eBee Using RTK and PPK Corrections Methods as a Function of Distance to a GNSS Base Station

The use of unmanned aircraft systems to collect data for photogrammetry models has grown significantly in recent years. The accuracy of a photogrammetric model can depend on image georeferencing. The distance from a reference base station can affect the accuracy of the results. Positioning corrections data relies on precise timing measurements of satellite signals. The signals travel through the Earth\u27s atmosphere, which introduces errors due to ionospheric and tropospheric delays. The aim of this research was to examine the eBee X and its global GNSS accuracy by comparing the RTK and PPK methods at different base station distances in photogrammetry models. Three factors were compared: 1) RTK and PPK methods, 2) local GNSS receiver via caster and NTRIP service corrections sources, and 3) base station distances between 2.4 km and 42.0 km. The eBee X flights occurred in 2023, at three different flying sites in Southwest Arizona in the United States. The RMSEXYZ values from eight Check Points at each of three flying sites were measured with traditional GNSS survey methods. Through ANOVA testing, there were no statistical differences in RMSEXYZ accuracy between RTK and PPK methods as well as between using a local Reach RS2 GNSS receiver via caster and NTRIP service for the eBee X; however, there was a statistical difference in RMSEXYZ accuracy between base station distances of 2.4 km to 42.0 km, whereas, F(5, 33) = 11.99, p = 0.000. Specifically, base station distances of less than 16.2 km were significantly less than larger distances up to 42.0 km. These data suggest there was a significant difference in total accuracy based on the distance from the GNSS receiver base station providing corrections for the eBee X

Heparin Isomeric Oligosaccharide Separation Using Volatile Salt Strong Anion Exchange Chromatography

The complexity of heparin and heparan sulfate saccharides makes their purification, including many isomeric structures, very challenging and is a bottleneck for structure–activity studies. High-resolution separations have been achieved by strong anion exchange (SAX) chromatography on Propac PA1 and cetyltrimethylammonium (CTA)-C18 silica columns; however, these entail subsequent desalting methodologies and consequent sample losses and are incompatible with orthogonal chromatography methodologies and, in particular, mass spectrometry. Here, we present the CTA-SAX purification of heparin oligosaccharides using volatile salt (VS) buffer. In VSCTA-SAX, the use of ammonium bicarbonate buffer for elution improves resolution through both weaker dissociation and conformational coordination of the ammonium across the sulfate groups. Using ion mobility mass spectrometry, we demonstrate that isomeric structures have different structural conformations, which makes chromatographic separation achievable. Resolution of such structures is improved compared to standard SAX methods, and in addition, VSCTA-SAX provides an orthogonal method to isolate saccharides with higher purity. Because ammonium bicarbonate is used, the samples can be evaporated rather than desalted, preventing substantial sample loss and allowing more effective subsequent analysis by electrospray mass spectrometry. We conclude that VSCTA-SAX is a powerful new tool that helps address the difficult challenge of heparin/heparan sulfate saccharide separation and will enhance structure–activity studies

Operational Assessment of Apollo Lunar Surface Extravehicular Activity

Quantifying the operational variability of extravehicular activity (EVA) execution is critical to help design and build future support systems to enable astronauts to monitor and manage operations in deep-space, where ground support operators will no longer be able to react instantly and manage execution deviations due to the significant communication latency. This study quantifies the operational variability exhibited during Apollo 14-17 lunar surface EVA operations to better understand the challenges and natural tendencies of timeline execution and life support system performance involved in surface operations. Each EVA (11 in total) is individually summarized as well as aggregated to provide descriptive trends exhibited throughout the Apollo missions. This work extends previous EVA task analyses by calculating deviations between planned and as-performed timelines as well as examining metabolic rate and consumables usage throughout the execution of each EVA. The intent of this work is to convey the natural variability of EVA operations and to provide operational context for coping with the variability inherent to EVA execution as a means to support future concepts of operations

Thin liquid water clouds: their importance and our challenge

Many clouds important to the Earth’s energy balance contain small amounts of liquid water, yet despite many improvements, large differences in retrievals of their liquid water amount and particle size still must be resolved