264 research outputs found
Late Cretaceous through Paleogene Reconstruction of Pacific Deep-Water Circulation
A growing body of Nd isotope data derived from fish debris and Fe-Mn crusts suggests that the Pacific was characterized by deep-water mass formation in both the North and South Pacific during the Early Paleogene. However, the South Pacific source has not been identified to date. Here we present new fossil fish debris neodymium isotope data from the South Pacific and southern tropical Pacific Ocean Drilling Program and Deep Sea Drilling Project Sites 323, 463, 596, 865 and 869 (paleowater depths spanning 1500 to 5000m) to reconstruct the water mass composition over the time interval ~80 to ~24 Ma.
The data indicate a relatively unradiogenic South Pacific water mass composition, and the composition of Nd increases with distance northward. The new tropical Pacific data are consistent with existing records from that region. Analyses of detrital sediment Nd isotopic composition, combined with the dissolved Nd composition recorded by fish debris, suggests that the South Pacific water mass convected in the Pacific sector of the Southern Ocean. We designate this water mass South Pacific Deep Water (SPDW). The Nd isotopic composition of SPDW is more radiogenic than initially hypothesized and the relatively small increase in isotopic composition (from ~-6 to ~-4) during the transit from the Southern Ocean to the tropical Pacific suggests a faster rate of overturning circulation during the greenhouse climate interval than previously thought
Implications of Diet for the Extinction of Saber-Toothed Cats and American Lions
The saber-toothed cat, Smilodon fatalis, and American lion, Panthera atrox, were among the largest terrestrial carnivores that lived during the Pleistocene, going extinct along with other megafauna ~12,000 years ago. Previous work suggests that times were difficult at La Brea (California) during the late Pleistocene, as nearly all carnivores have greater incidences of tooth breakage (used to infer greater carcass utilization) compared to today. As Dental Microwear Texture Analysis (DMTA) can differentiate between levels of bone consumption in extant carnivores, we use DMTA to clarify the dietary niches of extinct carnivorans from La Brea. Specifically, we test the hypothesis that times were tough at La Brea with carnivorous taxa utilizing more of the carcasses. Our results show no evidence of bone crushing by P. atrox, with DMTA attributes most similar to the extant cheetah, Acinonyx jubatus, which actively avoids bone. In contrast, S. fatalis has DMTA attributes most similar to the African lion Panthera leo, implying that S. fatalis did not avoid bone to the extent previously suggested by SEM microwear data. DMTA characters most indicative of bone consumption (i.e., complexity and textural fill volume) suggest that carcass utilization by the extinct carnivorans was not necessarily more complete during the Pleistocene at La Brea; thus, times may not have been tougher than the present. Additionally, minor to no significant differences in DMTA attributes from older (~30-35 Ka) to younger (~11.5 Ka) deposits offer little evidence that declining prey resources were a primary cause of extinction for these large cats
Nd Isotopic Structure of the Pacific Ocean 70-30 and Numerical Evidence for Vigorous Ocean Circulation and Ocean Heat Transport in a Greenhouse World
The oceanic meridional overturning circulation (MOC) is a crucial component of the climate system, impacting heat and nutrient transport, and global carbon cycling. Past greenhouse climate intervals present a paradox because their weak equator-to-pole temperature gradients imply a weaker MOC, yet increased poleward oceanic heat transport appears to be required to maintain these weak gradients. To investigate the mode of MOC that operated during the early Cenozoic, we compare new Nd isotope data with Nd tracer-enabled numerical ocean circulation and coupled climate model simulations. Assimilation of new Nd isotope data from South Pacific Deep Sea Drilling Project and Ocean Drilling Program Sites 323, 463, 596, 865, and 869 with previously published data confirm the hypothesized MOC characterized by vigorous sinking in the South and North Pacific ~70 to 30 Ma. Compilation of all Pacific Nd isotope data indicates vigorous, distinct, and separate overturning circulations in each basin until ~40 Ma. Simulations consistently reproduce South Pacific and North Pacific deep convection over a broad range of conditions, but cases using strong deep ocean vertical mixing produced the best data-model match. Strong mixing, potentially resulting from enhanced abyssal tidal dissipation, greater interaction of wind-driven internal wave activity with submarine plateaus, or higher than modern values of the geothermal heat flux enable models to achieve enhanced MOC circulation rates with resulting Nd isotope distributions consistent with the proxy data. The consequent poleward heat transport may resolve the paradox of warmer worlds with reduced temperature gradients
Developing a health sciences information literacy assessment for undergraduates.
This poster describes the development and pilot of a tailored information literacy assessment tool for undergraduate allied health students. Tool development included collaboration between assessment experts, Health Science faculty, and Health Science librarians. The poster includes results from the tool deployment and next steps in applying results back into revised curriculum
Biotests für ein effektbasiertes Monitoring: Schadstoffe - Ermittlung von Belastungspfaden
Die Belastung von Oberflächengewässern kann mit unterschiedlichen Methoden erfasst werden. Bioteste ergänzen die Ergebnisse der chemischen Analyse. Mit dem effektbasierten Monitoring lassen sich Risikopotentiale erfassen. Es sind Rückschlüsse auf die Art der Belastung möglich. Der Bericht enthält erste Ergebnisse für ausgewählte sächsische Fließgewässer.
Redaktionsschluss: 29.07.201
Lessons and Outcomes of Mobile Acute Care for Elders Consultation in a Veterans Affairs Medical Center
OBJECTIVE
Describe the implementation and effects of Mobile Acute Care for Elders (MACE) consultation at a Veterans Affairs Medical Center (VAMC).
DESIGN
Retrospective cohort analysis.
INTERVENTION
Veterans aged 65 or older who were admitted to the medicine service between October 1, 2012, and September 30, 2014, were screened for geriatric syndromes via review of medical records within 48 hours of admission. If the screen was positive, the MACE team offered the admitting team a same‐day consultation involving comprehensive geriatric assessment and ongoing collaboration with the admitting team and supportive services to implement patient‐centric recommendations for geriatric syndromes.
RESULTS
Veterans seen by MACE (n = 421) were compared with those with positive screens but without consultation (n = 372). The two groups did not significantly differ in age, comorbidity, sex, or race. All outcomes (30‐day readmission, 30‐day mortality, readmission costs) were in the expected direction for patients receiving MACE but did not reach statistical significance. Patients receiving MACE had lower odds of 30‐day readmission (11.9% vs 14.8%; odds ratio [OR] = 0.82; 95% confidence interval [CI] = 0.54‐1.25; p = .360) and 30‐day mortality (5.5% vs 8.6%; OR = 0.64; CI = 0.36‐1.12; p = .115), and they had lower 30‐day readmission costs (MACE 12,242‐18,335; CI = 22,962; p = .316) than those who did not receive MACE after adjusting for age and Charlson Comorbidity Index.
CONCLUSION
Our MACE consultation model for older veterans with geriatric syndromes leverages the limited supply of clinicians with expertise in geriatrics. Although not statistically significant in this study of 793 subjects, MACE patients had lower odds of 30‐day readmission and mortality, and lower readmission costs
Pseudo-monoamniotic Pregnancy: Case Report and Review of Etiologic Considerations
Pseudomonoamniotic gestations are increasingly recognized through sonographic surveillance of monochorionic twins, though etiologic factors remain undefined. We present a case of spontaneous pseudomonoamniotic twins and propose umbilical cord insertion proximity as a sonographic marker. Systematic review of the literature was performed and additional cases with similar findings were noted. Approximately 75% of reported cases (28/37) were deemed spontaneous and several included short inter-cord distances. Shunting of blood away from the membranes in the region between the cord insertions may be responsible for membrane rupture. Further investigation is needed into short inter-cord distance as a marker for monochorionic twins at risk to become a pseudomonoamniotic gestation
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