Cardiac sympathetic activity as measured by myocardial 123-I-metaiodobenzylguanidine uptake and heart rate variability in idiopathic dilated cardiomyopathy.

In patients with idiopathic dilated cardiomyopathy (IDC) the increased sympathetic activity owing to chronic congestive heart failure leads to an imbalance of cardiac autonomic tone, as reflected by decreased heart rate variability (HRV). Iodine-123-metaiodobenzylguanidine (123-I-MIBG), which has the same affinity for sympathetic nerve endings as norepinephrine, can be used to assess the integrity and function of the cardiac sympathetic nervous system. The aim of the present study was to measure cardiac sympathetic activity by assessing 123-I-MIBG uptake compared with HRV in patients with IDC. In 12 patients with IDC and mild to moderate heart failure, myocardial MIBG uptake was calculated from the myocardial (M) to left ventricular cavity (C) voxel values density ratio and the 123-I activity in a blood sample as a reference (= M/C ratio) using a double radionuclide study with 123-I-MIBG and technetium-99m-MIBI. To investigate the relation between myocardial MIBG uptake and HRV in time domain, the linear regression between the M/C ratio, a new scintigraphic parameter, and the mean RR interval or the HRV triangular index, respectively, was determined. A significant correlation between the M/C ratio and mean RR interval (r = 0.52; p = 0.016) or M/C ratio and HRV triangular index (r = 0.76; p = 0.003), respectively, was found. Thus, the significant correlation between the M/C ratio and HRV indicate that they are both suitable noninvasive methods for evaluating cardiac sympathetic activity in patients with IDC and, furthermore, favor the view that there is evidence of a relation between HRV and the disorder of the cardiac presynaptic sympathetic nerve endings as demonstrated by a reduced M/C ratio

Implementing atmospheric fate in regulatory risk assessment of pesticides: (how) can it be done?

Atmospheric fate of pesticides and their possible effects in ecosystems beyond the immediate surrounding of the application site are not actively considered in currently used regulatory, risk assessment schemes. Concern with respect to atmospheric transport and subsequent deposition of pesticides in non-target areas is however growing. In this article the results of discussions on the possibilities of implementing atmospheric fate in regulatory risk assessment are presented. It is concluded that implementing atmospheric fate in regulatory risk assessment schemes is possible and that, from a scientific point of view, these schemes should distinguish between pesticides on the basis of both their possibility/probability to reach non- target areas and on their toxicity. This implies that application of the precautionary principle or use of intrinsic pesticide properties alone is not considered justifiable. It is recommended that the risk assessment scheme should follow a tiered approach. The first tier should be entered only if the existing regulatory risk assessment procedure, including a local PEC:PNEC calculation, has been passed and involves a test for the pesticide's total atmospheric emission potential, i.e. its potential for becoming airborne during and after application. The second tier, which is only entered if the total emission potential is higher than a certain trigger value, should consist of a PEC:PNEC calculation for regional off-site areas (10-50 km) (tier 2A). If the pesticide's atmospheric transport potential is expected to exceed a certain value, the PEC:PNEC ratio should also be calculated for more remote areas (>1000 km) (tier 2B)

Creating Cultures of Teaching and Learning: Conveying Dance and Somatic Education Pedagogy

Often in teaching dance, methods of teaching and learning are silently embedded into dance classroom experiences. Unidentified and undisclosed pedagogic information has impacted the content of dance history; the perpetuation of authoritarian teaching practices within dance technique classes and in some dance classes deemed “somatics”; and the perception of the field of dance as “dance as art” or “dance as education”. This research illuminates a history of dance pedagogy in United States higher education. Dance pedagogy is aligned with current educational theory and practice, which reveals the impact of pedagogic choices on creating student-centered and teacher-centered cultures of teaching and learning. This article calls upon dance educators to be cognizant of the implications of pedagogic choices and to be transparent to students about pedagogy in their classrooms