Controls on carbonate and siliciclastic sediment deposition on a mixed carbonate-siliciclastic shelf (Pennsylvanian Eastern Shelf of north Texas)

Patterns and trends of carbonate and siliciclastic lithologies in late Paleozoic cyclothems are used as the basis for identifying the factors controlling deposition in mixed carbonate-siliciclastic systems. The cyclothems examined in detail occur on the Eastern Shelf of the Midland basin in north Texas. Cyclothems are products of deposition in shelfwide mixed carbonate-siliciclastic systems and contain an intermediate water depth carbonate zone positioned between a shallow nearshore zone of siliciclastic deposition and a deep-water outer shelf zone of siliciclastic deposition. Carbonate sedimentation was largely depth controlled, because carbonate sediment production was primarily from microbes, multicellular algae, or other light-controlled benthic organisms. Siliciclastic sedimentation in the noncarbonate outer shelf environments resulted from pulses of fine-grained siliciclastic sediment traversing the carbonate zone in storm-generated suspension clouds. Increased siliciclastic sediment input narrowed the carbonate zone on the shelf but did not greatly shift its central position. Cyclothem deposition corresponds to a limited range of conditions covered in a general model of mixed carbonate-siliciclastic deposition on shelf surfaces. The major variables in this model are the quantity and composition of siliciclastic sediment delivered to the shoreline and carried onto the shelf, the depth of the lower limit of the photic zone as it intersects the shelf surface, the gradient of the depositional surface, and the proportion of benthic production to planktic production of carbonate sediment. In systems where carbonate sediment is predominantly benthic in origin (Paleozoic and Triassic oceans), the first three variables are dominant and result in outer shelf siliciclastic deposition beyond a carbonate zone. In systems where planktic production of carbonate occurs (Jurassic to modern warm-water oceans), planktic production of carbonate tends to overwhelm benthic production and produces carbonate deposition on outer shelf surfaces. General patterns of sedimentation are set by the benthic/planktic production ratio and the gradient of the depositional surface, whereas specific patterns are produced by the amounts of siliciclastic sediment transported onto the shelf and the manner in which the photic zone intersects the shelf

Controls on carbonate and siliciclastic sediment deposition on a mixed carbonate-siliciclastic shelf (Pennsylvanian Eastern Shelf of north Texas)

Patterns and trends of carbonate and siliciclastic lithologies in late Paleozoic cyclothems are used as the basis for identifying the factors controlling deposition in mixed carbonate-siliciclastic systems. The cyclothems examined in detail occur on the Eastern Shelf of the Midland basin in north Texas. Cyclothems are products of deposition in shelfwide mixed carbonate-siliciclastic systems and contain an intermediate water depth carbonate zone positioned between a shallow nearshore zone of siliciclastic deposition and a deep-water outer shelf zone of siliciclastic deposition. Carbonate sedimentation was largely depth controlled, because carbonate sediment production was primarily from microbes, multicellular algae, or other light-controlled benthic organisms. Siliciclastic sedimentation in the noncarbonate outer shelf environments resulted from pulses of fine-grained siliciclastic sediment traversing the carbonate zone in storm-generated suspension clouds. Increased siliciclastic sediment input narrowed the carbonate zone on the shelf but did not greatly shift its central position. Cyclothem deposition corresponds to a limited range of conditions covered in a general model of mixed carbonate-siliciclastic deposition on shelf surfaces. The major variables in this model are the quantity and composition of siliciclastic sediment delivered to the shoreline and carried onto the shelf, the depth of the lower limit of the photic zone as it intersects the shelf surface, the gradient of the depositional surface, and the proportion of benthic production to planktic production of carbonate sediment. In systems where carbonate sediment is predominantly benthic in origin (Paleozoic and Triassic oceans), the first three variables are dominant and result in outer shelf siliciclastic deposition beyond a carbonate zone. In systems where planktic production of carbonate occurs (Jurassic to modern warm-water oceans), planktic production of carbonate tends to overwhelm benthic production and produces carbonate deposition on outer shelf surfaces. General patterns of sedimentation are set by the benthic/planktic production ratio and the gradient of the depositional surface, whereas specific patterns are produced by the amounts of siliciclastic sediment transported onto the shelf and the manner in which the photic zone intersects the shelf

Report on the public archives of Florida.

A report covering subject matter, condition, and availability of archival materials (exluding Spanish materials) relating to the history of Florida.https://stars.library.ucf.edu/floridaheritage/1132/thumbnail.jp

Invertebrate Abundance at Northern Bobwhite Brood Locations in the Rolling Plains of Texas

Northern bobwhite (Colinus virginianus), a bird of significant ecological and economic importance throughout the Rolling Plains region of Texas, has experienced significant population declines. Bobwhites have been the focus of extensive research for decades but little is known about foraging ecology of adults and chicks during post-hatch. Invertebrates are a key summer diet component for chicks, and supply the necessary proteins and minerals needed to fuel rapid body development. We examined brood-foraging sites to investigate invertebrate abundance. We radiomarked 121 bobwhite hens during winter-spring 2008 and 2009 and subsequently monitored 14 broods post-hatch. We collected invertebrate samples from 34 brood points and random paired-locations using sweep nets. Samples were sorted by Order to ascertain abundance and diversity. There was no difference in total abundance, abundance of Coleoptera, Hemiptera, Orthoptera, and Order diversity between brood and random locations. Northern bobwhite hens do not appear to select foraging sites based upon invertebrate abundance in the Rolling Plains of Texas

In vitro increase of mean corpuscular volume difference (dMCV) as a marker for serum hypertonicity in dogs.

Spurious increase in erythrocyte mean corpuscular volume (MCV) on automated cell analyzers is a well-characterized lab error in hypertonic patients. A difference between automated and manual MCV (dMCV) greater than 2 fl has been shown to predict hypertonicity in humans. The purpose of this study was to investigate dMCV as a marker for serum hypertonicity in dogs and to examine the relationship between dMCV and three methods of estimating serum tonicity: measured (OsM_M), calculated (OsM_C), and calculated effective (OsM_CE) osmolalities. OsM_C, OsM_CE, and dMCV were calculated from routine blood values and OsM_M was directly measured in 121 dogs. The dMCV of hypertonic dogs was significantly larger than that of normotonic dogs for all three osmolality methods. dMCV predicted hypertonicity as estimated by OsM_M better than it predicted hypertonicity as estimated by OsM_C and OsM_CE. A cutoff of 2.96 fl yielded the best sensitivity (76%) and specificity (71%) for hypertonicity estimated by OsMM

Massive perturbations to atmospheric sulfur in the aftermath of the Chicxulub impact

This project has received funding from the National Science foundation (EAR 1455258 to C.K.J), the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Grant 678812 to M.W.C.) and a University of St Andrews Global Fellowship (to C.K.J.).Sulfate aerosols have long been implicated as a primary forcing agent of climate change and mass extinction in the aftermath of the end-Cretaceous Chicxulub bolide impact. However, uncertainty remains regarding the quantity, residence time, and degree to which impact-derived sulfur transited the stratosphere, where its climatic impact would have been maximized. Here, we present evidence of mass-independent fractionation of sulfur isotopes (S-MIF) preserved in Chicxulub impact ejecta materials deposited in a marine environment in the Gulf Coastal Plain of North America. The mass anomalous sulfur is present in Cretaceous–Paleogene event deposits but also extends into Early Paleogene sediments. These measurements cannot be explained by mass conservation effects or thermochemical sulfate reduction and therefore require sulfur-bearing gases in an atmosphere substantially different from the modern. Our data cannot discriminate between potential source reaction(s) that produced the S-MIF, but stratospheric photolysis of SO2 derived from the target rock or carbonyl sulfide produced by biomass burning are the most parsimonious explanations. Given that the ultimate fate of both of these gases is oxidation to sulfate aerosols, our data provide direct evidence for a long hypothesized primary role for sulfate aerosols in the postimpact winter and global mass extinction.Publisher PDFPeer reviewe

A Study of Human Serum Sickness

Twelve patients with bone marrow failure, who were undergoing therapy with daily intravenous infusions of horse antithymocyte globulin, were studied for the development of serum sickness. Eleven of 12 patients developed typical signs and symptoms of serum sickness 8-13 days after the initiation of treatment. These included fever, malaise, cutaneous eruptions, arthralgias, gastrointestinal disturbances, and lymphadenopathy. Eleven of 12 patients developed high levels of circulating immune complexes during serum sickness. All 12 patients also had concomitant decreases of serum C3 and C4 levels. In addition to urticarial and/or morbilliform eruptions, 8 of 11 patients also developed a serpiginous band of erythema along the sides of the fingers, hands, toes, or feet as an early cutaneous sign of serum sickness. Direct immunofluorescence of lesional skin biopsies during serum sickness revealed deposits of immunoglobulin or complement in the walls of small cutaneous blood vessels in 3 of 5 patients. These findings indicate that circulating immune complexes play a central role in the pathophysiology of human serum sickness

Preliminary test estimation for the second order autoregression / 1992:107

Includes bibliographical references (p.17)

Distribution, composition and functions of gelatinous tissues in deep-sea fishes

Many deep-sea fishes have a gelatinous layer, or subdermal extracellular matrix, below the skin or around the spine. We document the distribution of gelatinous tissues across fish families (approx. 200 species in ten orders), then review and investigate their composition and function. Gelatinous tissues from nine species were analysed for water content (96.53 ± 1.78% s.d.), ionic composition, osmolality, protein (0.39 ± 0.23%), lipid (0.69 ± 0.56%) and carbohydrate (0.61 ± 0.28%). Results suggest that gelatinous tissues are mostly extracellular fluid, which may allow animals to grow inexpensively. Further, almost all gelatinous tissues floated in cold seawater, thus their lower density than seawater may contribute to buoyancy in some species. We also propose a new hypothesis: gelatinous tissues, which are inexpensive to grow, may sometimes be a method to increase swimming efficiency by fairing the transition from trunk to tail. Such a layer is particularly prominent in hadal snailfishes (Liparidae); therefore, a robotic snailfish model was designed and constructed to analyse the influence of gelatinous tissues on locomotory performance. The model swam faster with a watery layer, representing gelatinous tissue, around the tail than without. Results suggest that the tissues may, in addition to providing buoyancy and low-cost growth, aid deep-sea fish locomotion. © 2017 The Authors

Fishes of the hadal zone including new species, in situ observations and depth records of Liparidae

AbstractObservations and records for fish exceeding 6000m deep are few and often spurious. Recent developments in accessing and sampling the hadal zone 6000–11,000m) have led to an acceleration in new findings in the deep subduction trenches, particularly in the Pacific Ocean. This study describes the discovery of two new species of snailfish (Liparidae) from the Mariana Trench; the ‘Mariana snailfish’ (6198–8076m) and the ‘Ethereal snailfish’ (7939–8145m). These new findings represent respectively the deepest known specimen caught with corroborating depth data, and the deepest fish seen alive. Further specimens and observations of the Kermadec Trench snailfish, Notoliparis kermadecensis, are also presented, as well as the first hadal records of Synaphobranchidae and Zoarcidae (6068 and 6145m respectively) and a depth extension for the Macrouridae (maximum depth now 7012m). Details of these new snailfish specimens caught by baited trap and behaviour observations filmed by baited cameras are presented. An updated assessment of fishes from hadal depths is also reported