Bacteria as paleoenvironmental proxies: the study of a cave Pleistocene profile

Caves are well-known archives that preserve valuable information about the past, relevant for reconstructing past climates and environments. We sampled sediments from a 480 cm deep profile. 16S rRNA gene-based metabarcoding analyses were undertaken that complemented lithological logging, sedimentology, and Optically Stimulated Luminescence (OSL) dating. These analyses revealed different sedimentation conditions along the profile with various water inputs. The OSL age of the sediments places the profile between 74.7 ± 12.3 to 56 ± 8 ka (base to top). However, more recent reworking processes (during LGM – Last Glacial Maximum paleofloods) in the upper and lower passages of the cave might have occurred. Bacterial compositions changed with depth, from soil bacteria (present in the upper part of the sediment profile) to thermophilic/sulfurous bacteria (abundant in the deeper samples of the profile). Considering the thermophilic bacteria, we could only assume their origin from a surface of hot sulfurous, old thermal springs, or sapropel sediments

Non-compaction cardiomyopathy – brief review

Left ventricular non-compaction cardiomyopathy is a genetic disorder characterized by the presence of two myocardial layers with numerous prominent trabeculations and deep inter-trabecular recesses that communicate with the ventricular cavity. The diagnosis is often challenging because excessive trabeculations may also be a normal finding in performance athletes and black people. Echocardiography is the gold standard for diagnosis of this condition, but other useful diagnostic techniques may include cardiac magnetic resonance imaging, computed tomography, and contrast ventriculography. Moreover, newer echocardiographic methods such as three-dimensional imaging and speckle tracking analysis promise to improve the diagnosis of left ventricular non-compaction cardiomyopathy. The purpose of this paper is to review the pathogenesis, diagnosis, and management of this disease

Recent advances in echocardiography: strain and strain rate imaging [version 1; referees: 3 approved]

Deformation imaging by echocardiography is a well-established research tool which has been gaining interest from clinical cardiologists since the introduction of speckle tracking. Post-processing of echo images to analyze deformation has become readily available at the fingertips of the user. New parameters such as global longitudinal strain have been shown to provide added diagnostic value, and ongoing efforts of the imaging societies and industry aimed at harmonizing methods will improve the technique further. This review focuses on recent advances in the field of echocardiographic strain and strain rate imaging, and provides an overview on its current and potential future clinical applications

Can the subterranean fauna be used as proxy for past environmental changes? – the example of the Carpathians cave fauna

Carpathian Mountains were one of the main refuge areas during the climate changes of the Pleistocene and the Holocene in Europe and one of the richest regions in the world in subterranean (caves and associated habitats) endemic species. Nevertheless, the Carpathian Mountains subterranean fauna importance is underestimated especially due to dispersed information on its diversity and the scarcity of molecular studies in the area. Here, we present a first general view of the cave fauna hotspot represented by the Romanian Carpathians and the geological and historical processes that shaped the patterns of subterranean distribution and diversity at regional scale. The Carpathians are an amalgam of various geological units with complex paleogeographical evolution that is reflected in completely different species assemblages dominated by unit specific fauna groups. Phylogeography of Coleoptera and environmental parameters are adding to the general view at regional scale and offer additional explanation for this exceptional subterranean diversification in a non-Mediterranean region. We also use the example of the Carpathians cave fauna as proxy for past environmental changes in the area. Troglobionts are endemic on small areas and by studying their present distributions and phylogeny, past processes of landscape evolution on the surface can be better understood.

Experimental validation of the prestretch-strain relationship as a non-invasive index of left ventricular myocardial contractility.

BACKGROUND:The slope of the relationship between segmental PreS and total systolic shortening (S) has been proposed as a non-invasive index of left ventricular contractility. The aim of this study was to correlate this novel parameter to invasive gold standard measurements of contractility and to investigate how it is influenced by afterload. METHODS:In domestic pigs, afterload was increased by either balloon inflation in the aorta or by administration of phenylephrine while contractility was increased by dobutamine infusion. During all interventions, left ventricular pressure-volume measurements and trans-diaphragmatic two-dimensional echocardiographic images were acquired. The PreS-S slope was constructed from 18 segmental strain curves obtained by speckle tracking analysis and compared to the slope of the end systolic PV relationship (Emax) and the pre-load recruitable stroke work (PRSW). RESULTS:Sixteen datasets of increased contractility and afterload were analyzed. During dobutamine infusion, the LV volumes decreased (p<0.05) while ejection fraction increased (p<0.05). Emax, PRSW and the slope of the intra-ventricular PreS-S relation increased significantly during dobutamine infusion. Afterload increase led to increase in systolic blood pressure (105±16mmHg vs. 138±25mmHg; p<0.01) and decrease of LV stroke volume and ejection fraction (p<0.01). The PreS-S slope was not influenced by loading conditions in concordance with the PRSW findings. The absolute values of the PreS-S slope did not correlate with Emax or PRSW. However, the change of the PreS-S slope in relation with different interventions demonstrated good correlation with changes in PRSW or Emax, (r = 0.66, p<0.05 and r = 0.69, p<0.05). CONCLUSIONS:The slope of the PreS-S relationship is sensitive to changes in inotropy and is less load-dependent than conventional non-invasive parameters of left ventricular function. The magnitude of the change of this slope correlates well with changes in invasive contractility measurements making it an attractive parameter to assess contractile reserve or contractile changes during longitudinal follow-up of patients

Classification of longitudinal strain curves measured by speckle-tracking echocardiography in normal and pathological myocardial segments

Two-dimensional speckle-tracking echocardiography (2D-STE) provides a quantitative tool to evaluate LV function at the regional level. The purpose of this study was to classify the types of regional longitudinal strain curves (LSC). Moreover, we propose a novel longitudinal strain curve index (LSCI) which we compared to the wall motion score index (WMSI)

Image-based temporal alignment of echocardiographic sequences

Temporal alignment of echocardiographic sequences enables fair comparisons of multiple cardiac sequences by showing corresponding frames at given time points in the cardiac cycle. It is also essential for spatial registration of echo volumes where several acquisitions are combined for enhancement of image quality or forming larger field of view. In this study, three different image-based temporal alignment methods were investigated. First, a method based on dynamic time warping (DTW). Second, a spline-based method that optimized the similarity between temporal characteristic curves of the cardiac cycle using 1D cubic B-spline interpolation. Third, a method based on the spline-based method with piecewise modification. These methods were tested on in-vivo data sets of 19 echo sequences. For each sequence, the mitral valve opening (MVO) time was manually annotated. The results showed that the average MVO timing error for all methods are well under the time resolution of the sequences.status: publishe

Spatiotemporal registration of 3D volumetric echocardiographic images

status: accepte

3D Farnebäck Optic Flow for Extended Field of View of Echocardiography

status: publishe