HOW DO THEY DO IT? USING OMICS APPROACHES TO EXPLORE METABOLIC RESPONSES ASSOCIATED WITH HYPOXIA AND EXERCISE TOLERANCE IN THE DEEPEST DIVING PINNIPED

Marine mammals such as northern elephant seals (NES) routinely experience hypoxemia and ischemia-reperfusion events to many tissues during deep dives with no apparent adverse effects. Adaptations to diving include increased antioxidants and elevated oxygen storage capacity associated with high hemoprotein content in blood and muscle. Despite experiencing decreased oxygen tensions during diving, NES likely rely on the mobilization of large lipids stores and catabolism of fatty acids to provide energy to exercising muscle while diving. To identify potential regulatory mechanisms that may underly hypoxia and exercise tolerance in diving mammals, this study used system-wide approaches to characterize changes in genes and proteins in two metabolically active tissues (skeletal muscle and blubber) and whole blood of NES over development and in response to translocation. Specifically, this study profiled muscle and blood gene expression associated with regulation of oxidative stress and inflammatory pathways in weaned pups, juveniles, and adult NES as well as evaluated muscle and blubber transcriptomic and proteomic responses to swimming and diving in juvenile NES. I found that expression of genes associated with mitochondrial biogenesis (PGC1A, ESRRA, ESRRG), immune system activation (HMOX2, IL1B, NRF2, BVR, IL10), and protection from lipid peroxidation (GPX4, PRDX6, PRDX1, SIRT1) increased over postnatal development in muscle and whole blood of NES, providing a potential ontogenic mechanism for increasing diving capacity and hypoxia and ischemia-reperfusion tolerance. I also found that expression of genes and abundance of proteins associated with lipid transport (APOD, ABCA6, ABCA8, ABCA10, CD1E), lipid catabolism (ADIPOQ , ENPP6), and adipogenesis (DLK1, ADIRF,) increased, while those associated with insulin sensitivity and energy expenditure (APLN, VGF) decreased in response to swimming and diving in juvenile NES blubber and muscle, suggesting potential mechanisms for fuel provisioning to muscle during exercise in hypoxic conditions. Together, these data provide insights into gene activity in muscle, blubber, and blood cells that may provide hypoxia tolerance and regulate energy homeostasis and exercise performance during breath holds in diving mammals

Application of Hasse Diagrams for Counting Topologies on Finite Sets Technical Report No. 14

Diagram method for counting topologies on finite set

Proof without Words: On Sums of Squares and Triangles

author's final draft post-referee and pre-publication copySummary. We visually display a relationship between sums of squares and the sum of an even number of triangular numbers. Connections to some proofs without words appearing in the literature are briefly discussed.Ye

Multipurpose electric furnace system

A multipurpose electric furnace system of advanced design for space applications was developed and tested. This system is intended for use in the Apollo-Soyuz Test Program. It consists of the furnace, control package and a helium package for rapid cooldown

Reconstruction of east–west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years

Radiogenic neodymium isotopes have been used as a water mass mixing proxy to investigate past changes in ocean circulation. Here we present a new depth transect of deglacial neodymium isotope records measured on uncleaned planktic foraminifera from five cores spanning from 3300 to 4900 m on the Mauritanian margin, in the tropical eastern Atlantic as well as an additional record from 4000 m on the Ceara Rise in the equatorial western Atlantic. Despite being located under the Saharan dust plume, the eastern Atlantic records differ from the composition of detrital inputs through time and exhibit similar values to the western Atlantic foraminiferal Nd across the deglaciation. Therefore we interpret the foraminiferal values as recording deep water Nd isotope changes. All six cores shift to less radiogenic values across the deglaciation, indicating that they were bathed by a lower proportion of North Atlantic Deep Water during the Last Glacial Maximum (LGM) relative to the Holocene. The eastern Atlantic records also show that a neodymium isotope gradient was present during the LGM and during the deglaciation, with more radiogenic values observed at the deepest sites. A homogeneous water mass observed below 3750 m in the deepest eastern Atlantic during the LGM is attributed to the mixing of deep water by rough topography as it passes from the western Atlantic through the fracture zones in the Mid-Atlantic Ridge. This implies that during the LGM the low latitude deep eastern Atlantic was ventilated from the western Atlantic via advection through fracture zones in the same manner as occurs in the modern ocean. Comparison with carbon isotopes indicates there was more respired carbon in the deep eastern than deep western Atlantic during the LGM, as is also seen in the modern Atlantic Ocean.Radiocarbon analyses were supported by NERC radiocarbon grant 1752.1013 and Nd isotope analyses by NERC grants NERC NE/K005235/1 and NERC NE/F006047/1 to AMP. JNWH was supported by a Rutherford Memorial Scholarship

Spontaneous Bile Duct Rupture in Pregnancy

Spontaneous bile duct rupture occurred in a 23-year-old who required emergency Cesarean section for fetal distress. This condition has not been reported in association with pregnancy. Only forty cases of spontaneous bile duct perforation in adults have been previously reported. Seventy percent of these perforations were related to biliary calculi. Sites of perforation were evenly distributed between common hepatic duct and common bile duct. Recommended treatment includes cholecystectomy, common bile duct exploration, T-tube placement, and Roux-En-Y ductal anastomosis if disruption is extensive