Eocene–early Oligocene climate and vegetation change in southern China: Evidence from the Maoming Basin

Although the Eocene-Oligocene climate transition marks a critical point in the development of the ‘icehouse’ global climate of the present little is known about this important change in the terrestrial realm at low latitudes. Our palynological study of the Shangcun Formation shows it to be early Oligocene in age: palyno-assemblages in the lower part of the formation indicate a cool interval dominated by conifer pollen in the earliest Oligocene followed by a warmer regime in the second half of the early Oligocene. To quantify middle Eocene to late early Oligocene climate conditions at low (~ 20°N) palaeolatitudes in southern Asia several thousand leaf fossil specimens from the Maoming Basin, southern China, were subjected to a multivariate (CLAMP) analysis of leaf form. For terrestrial palaeoclimate comparisons to be valid the palaeoaltitude at which the proxy data are obtained must be known. We find that leaves preserved in the Youganwo (middle Eocene), Huangniuling (late Eocene) and Shangcun (early Oligocene) formations were likely to have been deposited well above sea level at different palaeoelevations. In the Youganwo Formation fine-grained sediments were deposited at an altitude of ~ 1.5 km, after which the basin dropped to ~ 0.5 km by the time the upper Huangniuling sediments were deposited. The basin floor then rose again by 0.5 km reaching an altitude of approximately 1 km in which the Shangcun Formation fine-grained sediments were accumulated. Within the context of these elevation changes the prevailing climates experienced by the Youganwo, Lower Huangniuling, Upper Huangniuling and Shangcun fossil floras were humid subtropical with hot summers and warm winters, but witnessed a progressive increase in rainfall seasonality. By the early Oligocene rainfall seasonality was similar to that of the modern monsoonal climate of Guangdong Province, southern China. All floras show leaf physiognomic spectra most similar to those growing under the influence of the modern Indonesia-Australia Monsoon, but with no evidence of any adaptation to today's South or East Asia Monsoon regimes. The Upper Huangniuling Flora, rich in dipterocarp plant megafossils, grew in the warmest conditions with the highest cold month mean temperature and at the lowest altitude

Cyclotron Analysis of Australian Atmospheric Contamination before and after the 1974 French Nuclear Tests in the Pacific

Atmospheric particulates collected around East Coast Australian cities and Port Moresby, just before and after the French Atomic Test Series of 1974 in the Pacific, have been analysed by proton activation using the Melbourne University Cyclotron. A number of elements, namely S, Ca, Ti, Cr, Fe, Ni, Cu, Zn, Se and Hg, ranging in concentrations from .001 ug/m3 to up to 3.27 ug/m3 have been detected. The changes observed in the concentrations of these elements in the two sets of samples, taken just before and just after the Atomic Tests, are attributed to Synoptic rather than Nuclear Fall-Out effects

Foliar physiognomic record of climatic conditions during dormancy: Climate Leaf Analysis Multivariate Program (CLAMP) and the cold month mean temperature

The extent to which the leaves of woody dicots encode in their physiognomy the climatic conditions that exist during dormancy was tested by sampling 20 sites along an approximately west-east transect across European Russia, the Crimean Peninsula, Western Siberia, and central Eastern Siberia. This transect encompassed the most extreme mean annual temperature range recorded in the modern world where vegetation exists. Climate Leaf Analysis Multivariate Program (CLAMP) revealed little change in calibration of the warm month mean temperature compared with the PHYSG3AR data set derived from less extreme sites primarily in North America and Japan, but significant change with respect to the cold month mean temperature (CMMT) calibration. Although CLAMP underestimated the CMMT by up to 9°C in the coldest sites, the addition of the transect sites improved CLAMP's performance at low temperatures. This suggests that winter cold is encoded in foliar physiognomy even though the leaves are functional only during the late spring and summer months. This increase in performance was, however, at the cost of decreasing precision. Precipitation predictive capabilities were only slightly affected, but calibration of key climatic variables such as enthalpy, used in determining palaeoaltitude, remained more or less unchanged after the inclusion of the cold transect samples. © 2004 by The University of Chicago. All rights reseved

The Dynamic Formation of Prominence Condensations

We present simulations of a model for the formation of a prominence condensation in a coronal loop. The key idea behind the model is that the spatial localization of loop heating near the chromosphere leads to a catastrophic cooling in the corona (Antiochos & Klimchuk 1991). Using a new adaptive grid code, we simulate the complete growth of a condensation, and find that after approx. 5,000 s it reaches a quasi-steady state. We show that the size and the growth time of the condensation are in good agreement with data, and discuss the implications of the model for coronal heating and SOHO/TRACE observations.Comment: Astrophysical Journal latex file, 20 pages, 7 b-w figures (gif files

Erratum: Identification of responsive cells in the developing somite supports a role for β‐catenin‐dependent Wnt signaling in maintaining the DML myogenic progenitor pool

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90355/1/23720_ftp.pd

Concept Mapping As A Tool To Promote Cognitive Integration

For 20 years there has been a push to integrate the basic and clinical sciences in medical school curricula. Recently, studies have suggested that cognitive integration by the student is best achieved when the relationships between basic science and clinical domains are explicitly demonstrated. Concept mapping in response to a prompt, which asks students to create relationships among clinical and basic science concepts, should provide explicit connections that lead to a deeper conceptual understanding of the material. We designed a study to test the hypothesis that concept mapping improves the ability of students to diagnostically discriminate between multiple endocrinopathies when compared to students who were provided with similar resources. We also looked to see if knowledge retention was correlated with concept mapping or the type of notes taken during studying.https://dune.une.edu/cetl_minigrant_posters/1001/thumbnail.jp

Medical Biochemistry Without Rote Memorization: Multi-Institution Implementation And Student Perceptions Of A Nationally Standardized Metabolic Map For Learning And Assessment

Despite the growing number of patients worldwide with metabolism-related chronic diseases, medical biochemistry education is commonly perceived as focusing on recall of facts irrelevant for patient care. The authors suggest that this focus on rote memorization of pathways creates excessive cognitive load that may interfere with learners’ development of an integrated understanding of metabolic regulation and dysregulation. This cognitive load can be minimized by providing appropriate references during learning and assessment. Biochemistry educators collaborated to develop a medically relevant Pathways of Human Metabolism map (MetMap) that is now being used at many medical schools as a nationally standardized resource during learning and assessments. To assess impact, students from three medical schools were surveyed about its benefits and disadvantages. Responses were obtained from 481 students (84%) and were examined using thematic analysis. Five main themes emerged as perceived benefits of using the MetMap: 1) aids visual and mental organization, 2) promotes deep learning and applied understanding, 3) decreases emphasis on memorization, 4) reduces anxiety on exams, and 5) aids recall. Perceived disadvantages were: 1) fear of under-preparation for licensing exams, 2) overwhelming nature of the map, and 3) reduced motivation for and time spent studying. Results affirm that students perceive use of the MetMap promotes focus on broader metabolic concepts and deep versus surface learning, supporting a shift in cognitive load toward desired goals. Although the long-term impact on learning needs to be further studied, the use of the MetMap represents a step toward open-reference exams that reflect “real world” practice

Student Perceptions Of Integrated Vs. Separate Basic Science And Clinical Resources

For 20 years there has been a push to integrate the basic and clinical sciences in medical school curricula. Recently, studies have suggested that cognitive integration is achieved when the relationships between basic science and clinical domains are explicitly demonstrated. In order to investigate methods that promote cognitive integration we performed a pilot study to develop and test different learning resources. We then surveyed students’ perceptions of these resources and analyzed how the resources affected their note taking. Our study suggests that the type of resources can influence the type of note-taking done by students, and that the process of taking integrated notes can enhance learning and retention. This was a pilot study and is limited by its small sample size. Additional research is planned to confirm and expand on these results.https://dune.une.edu/cetl_minigrant_posters/1000/thumbnail.jp