Cardiomyocyte Ca2+ handling and structure is regulated by degree and duration of mechanical load variation

Cardiac transverse (t)-tubules are altered during disease and may be regulated by stretch-sensitive molecules. The relationship between variations in the degree and duration of load and t-tubule structure remains unknown, as well as its implications for local Ca2+-induced Ca2+ release (CICR). Rat hearts were studied after 4 or 8 weeks of moderate mechanical unloading [using heterotopic abdominal heart–lung trans-plantation (HAHLT)] and 6 or 10 weeks of pressure overloading using thoracic aortic constriction. CICR, cell and t-tubule structure were assessed using confocal-microscopy, patch-clamping and scanning ion conductance microscopy. Moderate unloading was compared with severe unloading [using heart-only transplantation (HAHT)]. Mechanical unloading reduced cardiomyocyte volume in a time-dependent manner. Ca2+ release synchronicity was reduced at 8 weeks moderate unloading only. Ca2+ sparks increased in frequency and duration at 8 weeks of moderate unloading, which also induced t-tubule disorganization. Overloading increased cardiomyocyte volume and disrupted t-tubule mor-phology at 10 weeks but not 6 weeks. Moderate mechanical unloading for 4 weeks had milder effects compared with severe mechanical unloading (37 % reduction in cell volume at 4 weeks compared to 56 % reduction after severe mechanical unloading) and did not cause depres-sion and delay of the Ca2+ transient, increased Ca2+ spark frequency or impaired t-tubule and cell surface structure. These data suggest that variations in chronic mechanical load influence local CICR and t-tubule structure in a time- and degree-dependent manner, and that physiologi-cal states of increased and reduced cell size, without pathological changes are possible

Feasibility and reproducibility of left ventricular rotation by speckle tracking echocardiography in elderly individuals and the impact of different software

Background Changes in ventricular rotation measured by two-dimensional speckle tracking echocardiography (2DSTE) are early indicators of cardiac disease. Data on the clinical feasibility of this important measure are scarce and there is no information on the comparability of different software versions. We assessed the feasibility, reproducibility and within patient temporal variability of 2DSTE in a large community based sample of older adults. We additionally compared 2DSTE results to those generated by 3DSTE. Methods and results 1408 participants underwent transthoracic echocardiography. Using Philips Qlab 8.1 peak LV rotation at either the base or the apex was analysable in 432 (31%) participants. Peak twist measurements were achieved in 274 (20%) participants. 66 participants were randomly selected for the reproducibility study. 20 additional participants had scans 4–6 weeks apart for temporal variability and 3D echocardiography to assess the agreement between 2DSTE and 3DSTE. Reproducibility was evaluated using the intraclass coefficient of correlation (ICC). Better reproducibility for rotation and twist were obtained when measured at the endocardium, and when using more recent software versions, Peak twist and rotation were significantly different using two versions of the same software. Agreement with 3DSTE was better using newer software. Conclusion Feasibility of 2DSTE is low in this cohort of elderly individuals severely limiting its utility in clinical settings. However if high quality images can be acquired assessment of ventricular rotation by 2DSTE is reproducible. Caution should be taken when comparing measurements of ventricular rotation by software from different vendors or different versions of software from the same vendor

The effect of release time on dispersion of a fixed inventory of heavier than air gas A wind tunnel model study

SIGLEAvailable from British Library Document Supply Centre-DSC:2363.6665(149/96) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Indigenous techniques of catching mudskipper in Bhavnagar and Bharuch districts, Gujarat

533-538Indigenous fishing techniques for catching the mudskipper in Bhavnagar and Bharuch districts of Gujarat coast were investigated during 2014-15. The complexities of its muddy habitat and behaviour characteristics make it difficult to catch the mudskipper. Documentation on the fishing methods for catching the mudskipper is not available. This paper describes the two techniques namely- wire mesh technique and noose trap technique employed traditionally by the ethnic communities of fishermen to catch the mudskipper, encountered during the course of the survey. Wire mesh technique is used by fisher folk of Bhavnagar district whereas noose traps technique used by fisher folk of Bharuch district. Fisher folk of these two districts are able to earn their livelihood by these indigenous techniques in the areas which are known for low productivity of marine fishes due to their geomorphological features. Habitat destruction due to growing salt pan activities and industrial set up which leads to continuous shrinking of the mudflats used by fisher folk is the major concern for future livelihood aspects of the fisher folk of these districts