25 research outputs found
Genetics of Mechanosensation in the Heart
Mechanosensation (the ultimate conversion of a mechanical stimulus into a biochemical signal) as well as mechanotransduction (transmission of mechanically induced signals) belong to the most fundamental processes in biology. These effects, because of their dynamic nature, are particularly important for the cardiovascular system. Therefore, it is not surprising that defects in cardiac mechanosensation, are associated with various types of cardiomyopathy and heart failure. However, our current knowledge regarding the genetic basis of impaired mechanosensation in the cardiovascular system is beginning to shed light on this subject and is at the centre of this brief review
Synergids and filiform apparatus in the sexual and apomictic dandelions from section Palustria (Taraxacum, Asteraceae)
An evolutionary trend to reduce “unnecessary costs” associated with the sexual reproduction of their amphimictic ancestors, which may result in greater reproductive success, has been observed among the obligatory apomicts. However, in the case of the female gametophyte, knowledge about this trend in apomicts is not sufficient because most of the ultrastructural studies of the female gametophyte have dealt with amphimictic angiosperms. In this paper, we tested the hypothesis that, in contrast to amphimictic plants, synergids in apomictic embryo sacs do not form a filiform apparatus. We compared the synergid structure in two dandelions from sect. Palustria: the amphimictic diploid Taraxacum tenuifolium and the apomictic tetraploid, male-sterile Taraxacum brandenburgicum. Synergids in both species possessed a filiform apparatus. In T. brandenburgicum, both synergids persisted for a long time without any degeneration, in spite of the presence of an embryo and endosperm. We propose that the persistent synergids in apomicts may play a role in the transport of nutrients to the embryo
Aerobic Training in Rats Increases Skeletal Muscle Sphingomyelinase and Serine Palmitoyltransferase Activity, While Decreasing Ceramidase Activity
Sphingolipids are important components of cell membranes that may also serve as cell signaling molecules; ceramide plays a central role in sphingolipid metabolism. The aim of this study was to examine the effect of 5 weeks of aerobic training on key enzymes and intermediates of ceramide metabolism in skeletal muscles. The experiments were carried out on rats divided into two groups: (1) sedentary and (2) trained for 5 weeks (on a treadmill). The activity of serine palmitoyltransferase (SPT), neutral and acid sphingomyelinase (nSMase and aSMase), neutral and alkaline ceramidases (nCDase and alCDase) and the content of sphingolipids was determined in three types of skeletal muscle. We also measured the fasting plasma insulin and glucose concentration for calculating HOMA-IR (homeostasis model assessment) for estimating insulin resistance. We found that the activities of aSMase and SPT increase in muscle in the trained group. These changes were followed by elevation in the content of sphinganine. The activities of both isoforms of ceramidase were reduced in muscle in the trained group. Although the activities of SPT and SMases increased and the activity of CDases decreased, the ceramide content did not change in any of the studied muscle. Although ceramide level did not change, we noticed increased insulin sensitivity in trained animals. It is concluded that training affects the activity of key enzymes of ceramide metabolism but also activates other metabolic pathways which affect ceramide metabolism in skeletal muscles
A Social Sciences and Humanities research agenda for transport and mobility in Europe: key themes and 100 research questions
Transport and mobility systems need to be transformed to meet climate change goals and reduce negative environmental and social effects. Despite EU policies having targeted such problems for more than three decades, transitions have been slow and geographically uneven. For effective change to happen, transport and mobility research needs fresh perspectives and better integration of knowledge from the Social Sciences and Humanities. Based on a Horizon Scanning approach, which allowed for a great deal of openness and variety in scholarly viewpoints, this paper presents a novel research agenda consisting of 8 themes and 100 research questions that may contribute to achieving environmentally sustainable mobility transitions within Europe. This research agenda highlights the need to not only support technological solutions for low-carbon mobility, but the importance of transformative policies that include new processes of knowledge production, civic participation and epistemic justice. We contend that the agenda points to the need for further research on the dynamics of science-society interactions
A double-blind placebo-controlled investigation into the effects of interferential therapy on experimentally induced pain using a cross-over design
Objectives: To investigate the analgesic effect of interferential therapy (IFT) on experimentally induced anterior knee pain. Methods: A double-blind placebo-controlled investigation was undertaken on 10 healthy subjects. Anterior knee pain was induced by an injection of hypertonic saline into the medial infrapatellar fat pad. Immediately, following the injection, subjects received 20 minutes of each of the following conditions: control, placebo IFT, 4 Hz IFT, or 100 Hz IFT, in random order on four separate days. Pain severity and the size of the painful region every 30 seconds were recorded until pain ceased. The location of the pain was recorded at 2, 7, and 12 minutes after the painful injection using a standardized figure of the knee divided into nine segments. Results: There was no effect of condition on pain severity, size of painful area, maximum reported pain severity, maximum size of painful area, duration of pain, total pain severity, and the total size of the painful area (all P > 0.09). There was no interaction between time and condition on pain severity and size of painful area (P > 0.05). However, the location of pain was more dispersed at 7 minutes in the control condition (8/9 segments) compared with the placebo, 4 and 100 Hz conditions (2/9, 1/9, and 3/9 segments, respectively). Discussion: This preliminary study indicates that IFT is not effective at reducing acute experimentally induced pain when the severity or size of the painful area is measured. However, IFT may be effective by limiting pain spreading from the source. Further research with a larger sample size is required