Sea-surface temperature (SST) estimates of ~30 °C from planktic foraminifera and archaeal membrane lipids in bathyal sediments in the Canterbury Basin, New Zealand, support paleontological evidence for a warm subtropical to tropical climate in the early Eocene high-latitude (55°S) southwest Pacifi c. Such warm SSTs call into question previous estimates based on oxygen isotopes and present a major challenge to climate modelers. Even under hypergreenhouse conditions (2240 ppm CO 2 ), modeled summer SSTs for the New Zealand region do not exceed 20 °C. on June 6, 2015 geology.gsapubs.org Downloaded from

Use of combined hemodynamic and echocardiographic ramp tests in patients provides objective means of optimizing RPM, and has the potential to guide medical management. It remains to be tested whether this strategy has a beneficial impact on quality of life or clinical outcomes.

Transgenic mice displaying abnormalities in cardiac development and function represent a powerful new tool for understanding molecular mechanisms underlying normal cardiovascular function and the pathophysiological bases of human cardiovascular disease. Complete cardiac evaluation of phenotypic changes in mice requires the ability to noninvasively assess cardiovascular structure and function in a serial manner. However, the small mouse heart beating at rates in excess of 500 beats/min presents unique methodological challenges. Two-dimensional and Doppler echocardiography have been recently used as effective, noninvasive tools for murine imaging, because quality images of cardiac structures and valvular flows can be obtained with newer high-frequency transthoracic transducers. We will discuss the use of echocardiography for the assessment of 1) left ventricular (LV) chamber dimensions and wall thicknesses, 2) LV mass, 3) improved endocardial border delineation using contrast echocardiography, 4) LV contractility using ejection phase indices and load-independent indices, 5) vascular properties, and 6) LV diastolic performance. Evaluation of cardiovascular performance in closed chest mice is feasible in a variety of murine models using Doppler echocardiographic imaging. Doppler echocardiography; left ventricular performance GENETIC MODIFICATIONS are frequently used to produce mice models that are used to investigate the molecular basis of cardiac growth and development (7-9, 18, 24, 25) These technologies have led to a proliferation of transgenic and knockout mice models displaying a variety of cardiovascular phenotypes. To evaluate these phenotypes, it is necessary to develop accurate, reproducible, and noninvasive methods to assess cardiac morphology and function in a serial manner.Although it is currently possible to assess cardiac hemodynamics and function using ventricular catheterization, radiolabeled microspheres, and thermodilution techniques in mice, these methods require invasive instrumentation, which restrict the ability to measure physiological changes in a serial manner. Ultrasound imaging has been increasingly applied to identify and characterize structural and functional features of different cardiac phenotypes and pathophysiological responses to surgical and pharmacological interventions in large animal models of human disease (7-9, 16, 17, 27, 43). The small size of the mouse heart, which beats at heart rates in excess of 500 beats/min, presents unique methodological challenges for cardiac ultrasound. Recently developed broadband, phased-array, and linear transducers have small footprints, which are capable of both high frame-rate imaging and improved nearfield imaging, thereby generating high-quality images of the mouse heart.Imaging of the small, fast-beating murine hearts also requires special technical attention to the selection of proper anesthesia. In addition to anesthetic effects, in this review, we will discuss the preparation for image acquisition using currently available echocardiogr...

Genetically modified mice have created the need for accurate noninvasive left ventricular mass (LVM) measurements. Recent technical advances provide two-dimensional images adequate for LVM calculation using the area-length method, which in humans is more accurate than M-mode methods. We compared the standard M-mode and area-length methods in mice over a wide range of LV sizes and weights (62-210 mg). Ninety-one CD-1 mice (38 normal, 44 aortic banded, and 9 inherited dilated cardiomyopathy) were imaged transthoracically (15 MHz linear transducer, 120 Hz). Compared with necropsy weights, area-length measurements showed higher correlation than the M-mode method (r = 0.92 vs. 0.81), increased accuracy (bias +/- SD: 1.4 +/- 27.1% vs. 36.7 +/- 51.6%), and improved reproducibility. There was no significant difference between end-systolic and end-diastolic estimates. The truncated ellipsoid estimation produced results similar in accuracy to the area-length method. Whereas current echocardiographic technology can accurately and reproducibly estimate LVM with the two-dimensional, area-length formula in a variety of mouse models, additional technological improvements, rather than refinement of geometric models, will likely improve the accuracy of this methodology.

Abstract. We have monitored the temperature field within first-year sea ice in McMurdoSound over two winter seasons, with sufficient resolution to determine the thermal conductivity from the thermal waves propagating down through the ice. Data reduction has been accomplished by direct reference to energy conservation, relating the rate of change of the internal energy density to the divergence of the heat current density. Use of this procedure, rather than the wave attenuation predicted by the thermal diffusion equation, avoids difficulties arising from a strongly temperature dependent thermal diffusivity. The thermal conductivity is an input parameter for ice growth and climate models, and the values commonly used in the models are predicted to depend on temperature, salinity, and the volume fraction of air. The present measurements were performed at depths in the ice where the air volume is small and the salinity is nearly constant, and they permit the determination of the absolute magnitude of the thermal conductivity and its temperature dependence. The weak temperature dependence is similar to that predicted by the models in the literature, but the magnitude is smaller by • 10% than the predicted value most commonly used in climate and sea ice models. In the first season we find an additional scatter in the results at driving temperature gradients larger than •10-15 øC/m. We suggest that the scatter arises from a nonlinear contribution to the heat current, possibly associated with the onset of convective motion in brine inclusions. Episodic convective events are also observed. We have further determined the growth rate of the ice and compared it with the rate explained by the heat flux from the ice-water interface. The data show a sudden rise of growth rate, without a rise in heat flux through the ice, which coincides in time and depth with the appearance of platelet ice. Finally, we discuss the observation of radiative solar heating at depth in the ice and demonstrate that the absorption exceeds that in the ice alone; dust or algae must contribute to the absorption.

Functional diversity is an important aspect of biodiversity, but its relationship to species diversity in time and space is poorly understood. Here we compare spatial patterns of functional and taxonomic diversity across marine and terrestrial systems to identify commonalities in their respective ecological and evolutionary drivers. We placed species-level ecological traits into comparable multi-dimensional frameworks for two model systems, marine bivalves and terrestrial birds, and used global speciesoccurrence data to examine the distribution of functional diversity with latitude and longitude. In both systems, tropical faunas show high total functional richness (FR) but low functional evenness (FE) (i.e. the tropics contain a highly skewed distribution of species among functional groups). Functional groups that persist toward the poles become more uniform in species richness, such that FR declines and FE rises with latitude in both systems. Temperate assemblages are more functionally even than tropical assemblages subsampled to temperate levels of species richness, suggesting that high species richness in the tropics reflects a high degree of ecological specialization within a few functional groups and/or factors that favour high recent speciation or reduced extinction rates in those groups.royalsocietypublishing.org/journal/rspb Proc. R. Soc. B 286: 20190745

Background-Echocardiographic contrast media have been used to assess myocardial perfusion and to enhance endocardial definition for improved assessment of left ventricular (LV) function. These methodologies, however, have been qualitative or have required extensive offline image analysis. Power modulation is a recently developed imaging technique that provides selective enhancement of microbubble-generated reflections. Our goal was to test the feasibility of using power modulation for combined quantitative assessment of myocardial perfusion and regional LV function in an animal model of acute ischemia. Methods and Results-Coronary balloon occlusions were performed in 18 anesthetized pigs. Transthoracic power modulation images (Agilent 5500) were obtained during continuous intravenous infusion of the contrast agent Definity (DuPont) at baseline and during brief coronary occlusion and reperfusion and were analyzed with custom software. At each phase, myocardial perfusion was assessed by calculation, in 6 myocardial regions of interest, of mean pixel intensity and the rate of contrast replenishment after high-power ultrasound impulses. LV function was assessed by calculation of regional fractional area change from semiautomatically detected endocardial borders. All ischemic episodes caused detectable and reversible changes in perfusion and function. Perfusion defects, validated with fluorescent microspheres, were visualized in real time and confirmed by a significant decrease in pixel intensity in the left anterior descending coronary artery territory after balloon inflation and reduced rate of contrast replenishment. Fractional area change decreased significantly in ischemic segments and was restored with reperfusion. Conclusions-Power modulation allows simultaneous online assessment of myocardial perfusion and regional LV wall motion, which may improve the echocardiographic diagnosis of myocardial ischemia.

ABSTRACT. We report the first r esults from a programme recently se t up to directly measure the thermal conductivity of young sea ice.An array of thermistors frozen into first-year Antarctic sea ice provides temperature vs depth data, which is fitted directly with a partial diITerential equation for heat conduction.Temperatures are recorded every hour at 20 vertical intervals of 100 mm over a period of 5 months, allowing accurate and direct estimation of the thermal cond uctivity. Preliminary results indicate that the thermal conductivity is in the expected range, with some evidence of non-linear effects deeper in the ice. A larger variance in data is evident at higher temperature gradients a nd at greater depths in the ice.Preliminary modelling of the impact of brine migration on heat transport through first-year sea ice is presented. Diffusion-driven brin e pocket migration is too slow to contribute significantly to heat flow, but the convective instability of inclined brine slots or tubes is a promising m echanism.