Composition of the early Oligocene ocean from coral stable isotope and elemental chemistry

A sectioned and polished specimen of the coral Archohelia vicksburgensis from the early Oligocene Byram Formation (∼30 Ma) near Vicksburg, Mississippi, reveals 12 prominent annual growth bands. Stable oxygen isotopic compositions of 77 growth-band-parallel microsamples of original aragonite exhibit well-constrained fluctuations that range between −2.0 and −4.8. Variation in Δ 18 O of coral carbonate reflects seasonal variation in temperature ranging from 12 to 24 °C about a mean of 18 °C. These values are consistent with those derived from a bivalve and a fish otolith from the same unit, each using independently derived palaeotemperature equations. Mg/Ca and Sr/Ca ratios were determined for 40 additional samples spanning five of the 12 annual bands. Palaeotemperatures calculated using elemental-ratio thermometers calibrated on modern corals are consistently lower; mean temperature from Mg/Ca ratios are 12.5 ± 1 °C while those from Sr/Ca are 5.8 ± 2.2 °C. Assuming that Δ 18 O-derived temperatures are correct, relationships between temperature and elemental ratio for corals growing in today's ocean can be used to estimate Oligocene palaeoseawater Mg/Ca and Sr/Ca ratios. Calculations indicate that early Oligocene seawater Mg/Ca was ∼81% (4.2 mol mol −1 ) and Sr/Ca ∼109% (9.9 mmol mol −1 ) of modern values. Oligocene seawater with this degree of Mg depletion and Sr enrichment is in good agreement with that expected during the Palaeogene transition from ‘calcite’ to ‘aragonite’ seas. Lower Oligocene Mg/Ca probably reflects a decrease toward the present day in sea-floor hydrothermal activity and concomitant decrease in scavenging of magnesium from seawater. Elevated Sr/Ca ratio may record lesser amounts of Oligocene aragonite precipitation and a correspondingly lower flux of strontium into the sedimentary carbonate reservoir than today.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72914/1/j.1472-4677.2004.00025.x.pd

Ensemble Concerts: A Concert of Songs by Ned Rorem, May 15, 1971

CE-Lecture HallMay 15, 19718:00 p.m

Development of Methods of Increasing Terminal Flexibility and Control Authority: Option Year 1 Final Report

The focus of the NRA contract is to develop a What-if Analysis Tool for planning Departure Management Programs (DMP) at airports. This final report summarizes the work conducted throughout the option year, with a focus on use case specification for the what-if analysis capability and the implementation of the What-if Analysis Tool and its application to traffic and weather scenarios at Charlotte Douglas International Airport (CLT)

Overcoming the barriers to the diagnosis and management of chronic fatigue syndrome/ME in primary care: a meta synthesis of qualitative studies

Background The NICE guideline for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) emphasises the need for an early diagnosis in primary care with management tailored to patient needs. However, GPs can be reluctant to make a diagnosis and are unsure how to manage people with the condition. Methods A meta synthesis of published qualitative studies was conducted, producing a multi-perspective description of barriers to the diagnosis and management of CFS/ME, and the ways that some health professionals have been able to overcome them. Analysis provided second-order interpretation of the original findings and developed third-order constructs to provide recommendations for the medical curriculum. Results Twenty one qualitative studies were identified. The literature shows that for over 20 years health professionals have reported a limited understanding of CFS/ME. Working within the framework of the biomedical model has also led some GPs to be sceptical about the existence of the condition. GPs who provide a diagnosis tend to have a broader, multifactorial, model of the condition and more positive attitudes towards CFS/ME. These GPs collaborate with patients to reach agreement on symptom management, and use their therapeutic skills to promote self care. Conclusions In order to address barriers to the diagnosis and management of CFS/ME in primary care, the limitations of the biomedical model needs to be recognised. A more flexible bio-psychosocial approach is recommended where medical school training aims to equip practitioners with the skills needed to understand, support and manage patients and provide a pathway to refer for specialist input

Cardiovascular Magnetic Resonance Characterization of Mitral Valve Prolapse

ObjectivesThis study sought to develop cardiovascular magnetic resonance (CMR) diagnostic criteria for mitral valve prolapse (MVP) using echocardiography as the gold standard and to characterize MVP using cine CMR and late gadolinium enhancement (LGE)-CMR.BackgroundMitral valve prolapse is a common valvular heart disease with significant complications. Cardiovascular magnetic resonance is a valuable imaging tool for assessing ventricular function, quantifying regurgitant lesions, and identifying fibrosis, but its potential role in evaluating MVP has not been defined.MethodsTo develop CMR diagnostic criteria for MVP, characterize mitral valve morphology, we analyzed transthoracic echocardiography and cine CMR images from 25 MVP patients and 25 control subjects. Leaflet thickness, length, mitral annular diameters, and prolapsed distance were measured. Two- and three-dimensional LGE-CMR images were obtained in 16 MVP and 10 control patients to identify myocardial regions of fibrosis in MVP.ResultsWe found that a 2-mm threshold for leaflet excursion into the left atrium in the left ventricular outflow tract long-axis view yielded 100% sensitivity and 100% specificity for CMR using transthoracic echocardiography as the clinical gold standard. Compared with control subjects, CMR identified MVP patients as having thicker (3.2 ± 0.1 mm vs. 2.3 ± 0.1 mm) and longer (10.5 ± 0.5 mm/m2 vs. 7.1 ± 0.3 mm/m2) indexed posterior leaflets and larger indexed mitral annular diameters (27.8 ± 0.7 mm/m2 vs. 21.5 ± 0.5 mm/m2 for long axis and 22.9 ±0.7 mm/m2 vs. 17.8 ± 0.6 mm/m2 for short axis). In addition, we identified focal regions of LGE in the papillary muscles suggestive of fibrosis in 10 (63%) of 16 MVP patients and in 0 of 10 control subjects. Papillary muscle LGE was associated with the presence of complex ventricular arrhythmias in MVP patients.ConclusionsCardiovascular magnetic resonance image can identify MVP by the same echocardiographic criteria and can identify myocardial fibrosis involving the papillary muscle in MVP patients. Hyperenhancement of papillary muscles on LGE is often present in a subgroup of patients with complex ventricular arrhythmias

PERP, a host tetraspanning membrane protein, is required for Salmonella-induced inflammation

Salmonella enterica Typhimurium induces intestinal inflammation through the activity of type III secreted effector (T3SE) proteins. Our prior results indicate that the secretion of the T3SE SipA and the ability of SipA to induce epithelial cell responses that lead to induction of polymorphonuclear transepithelial migration are not coupled to its direct delivery into epithelial cells from Salmonella. We therefore tested the hypothesis that SipA interacts with a membrane protein located at the apical surface of intestinal epithelial cells. Employing a split ubiquitin yeast-two-hybrid screen, we identified the tetraspanning membrane protein, p53 effector related to PMP-22 (PERP), as a SipA binding partner. SipA and PERP appear to have intersecting activities as we found PERP to be involved in proinflammatory pathways shown to be regulated by SipA. In sum, our studies reveal a critical role for PERP in the pathogenesis of S. Typhimurium, and for the first time demonstrate that SipA, a T3SE protein, can engage a host protein at the epithelial surface

A systematic approach to designing reliable VV optimization methodology: Assessment of internal validity of echocardiographic, electrocardiographic and haemodynamic optimization of cardiac resynchronization therapy

AbstractBackgroundIn atrial fibrillation (AF), VV optimization of biventricular pacemakers can be examined in isolation. We used this approach to evaluate internal validity of three VV optimization methods by three criteria.Methods and resultsTwenty patients (16 men, age 75±7) in AF were optimized, at two paced heart rates, by LVOT VTI (flow), non-invasive arterial pressure, and ECG (minimizing QRS duration). Each optimization method was evaluated for: singularity (unique peak of function), reproducibility of optimum, and biological plausibility of the distribution of optima.The reproducibility (standard deviation of the difference, SDD) of the optimal VV delay was 10ms for pressure, versus 8ms (p=ns) for QRS and 34ms (p<0.01) for flow.Singularity of optimum was 85% for pressure, 63% for ECG and 45% for flow (Chi2=10.9, p<0.005).The distribution of pressure optima was biologically plausible, with 80% LV pre-excited (p=0.007). The distributions of ECG (55% LV pre-excitation) and flow (45% LV pre-excitation) optima were no different to random (p=ns).The pressure-derived optimal VV delay is unaffected by the paced rate: SDD between slow and fast heart rate is 9ms, no different from the reproducibility SDD at both heart rates.ConclusionsUsing non-invasive arterial pressure, VV delay optimization by parabolic fitting is achievable with good precision, satisfying all 3 criteria of internal validity. VV optimum is unaffected by heart rate. Neither QRS minimization nor LVOT VTI satisfy all validity criteria, and therefore seem weaker candidate modalities for VV optimization. AF, unlinking interventricular from atrioventricular delay, uniquely exposes resynchronization concepts to experimental scrutiny

Left Atrial scar assessment using imaging with isotropic spatial resolution and compressed sensing

Summary. We assess left atrial scar using late gadolinium enhancement (LGE) with isotropic spatial resolution of $1.4^3 mm^3$ by using highly accelerated LOST [1] reconstruction. Background. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia [2]. Pulmonary vein isolation (PVI) using radiofrequency (RF)-ablation is the leading treatment for AF. Recently, LGE imaging of the LA has been used to identify atrial wall scar due to RF-ablation [3]. However, current LGE methods have limited spatial resolution that substantially impact assessment of scar in the complex geometry of PVs and LA. In this study, we sought to utilize prospective random k-space sampling and LOST [1] for accelerated LGE imaging, where reduction in imaging time was traded-off for improved isotropic spatial-resolution. Methods. 23 patients with history of AF (6 females, $58.1 \pm 9.6$ years, 9 pre-PVI, 2 with history of PVI; 8 post-PVI; 3 with both pre and post-PVI) were recruited for this study. LGE images were acquired 10-to-20 minutes after bolus infusion of 0.2 mmol/kg Gd-DTPA. Free-breathing ECG-triggered navigator-gated inversion-recovery GRE sequences were used for all acquisitions ($TR/TE/ \alpha = 5.2/2.6ms/25°, FOV=320×320×100mm$). The PV inflow artifact reduction technique in [4] was also utilized. For each patient, a standard non-isotropic 3D LGE scan ($1.4×1.4×4.0mm^3$) and a 3-fold-accelerated highresolution 3D LGE scan ($1.4^3 mm^3$) were performed, with randomized acquisition order. For random undersampling, central k-space (45×35 in ky-kz) was fullysampled, edges randomly discarded, and phase reordering performed as in [5]. Acquisition times were ~4 mins assuming 100% scan-efficiency at 70bpm for both scans. All undersampled data were reconstructed offline using LOST [1]. LOST-reconstructed high-resolution, and standard LGE images were scored by two blinded readers for diagnostic value, presence of LGE(yes/no); and image quality in axial(Ax), coronal(Co) and sagittal (Sa) views (1=poor,4=excellent). Results. Three cases were declared non-diagnostic due to contrast-washout and imperfect inversion-time. LGE was visually present in 14 of the remaining 20 patients based on standard-LGE images, and 12 based on LOST-reconstructed ones (disagreement on one pre- and one postPVI patient). Figure 1 and 2 show comparisons of isotropic vs. non-isotropic LGE images in two patients. Image scores for LOST-LGE: $Ax=2.90 \pm 0.70, Sa=3.33 \pm 0.66, Co=3.00 \pm 0.63$; and standard LGE: $Ax=3.76 \pm 0.54, Sa=2.48 \pm 0.60, Co=2.24 \pm 0.44$, where differences were significant in all views. Conclusions. LOST allows isotropic spatial-resolution in LGE for assessment of LA and PV scar. Isotropic resolution allows reformatting LGE images in any orientation and facilitates assessment of scar. Further clinical study is needed to assess if the improved spatial resolution will impact the diagnostic interpretation of data

BiblioBouts: A Scalable Online Social Game for the Development of Academic Research Skills

Researchers at the School of Information of the University of Michigan are designing, developing, and evaluating BiblioBouts, an online game that helps students learn academic research skills. Players practice using online library research tools while they work on an in-class assignment and produce a high-quality bibliography, at the same time as they are competing against each other to win the game! While librarians are experts at helping students who want to learn about academic research, most students are reluctant participants because they want just-in-time personal assistance that is tailored to their unique information needs, and faculty are reluctant to cede class time. The BiblioBouts project enlists games to teach undergraduate students information literacy skills and concepts in the classroom. Social gaming reinforces principles of good learning, including getting results by trial and error, self-discovery, following hunches and reinforcement through repetition. BiblioBouts also incorporates collaborative problem solving and participation in a community of learning. The project aims to explore how games can be utilized to achieve information literacy goals and to yield open-source game software that libraries could use immediately to enhance their information literacy programs. The LOEX presentation will incorporate a live interactive demo of the game, as well as videos demonstrating gameplay. We will discuss challenges in situating the game into the classroom and integrating it into existing course syllabi. The presentation will describe how we have adapted the game in response to feedback from students and instructors during the pilot process