INTRODUCTION Physiological fluctuations due to respiration are the dominant source of confounding variability in BOLD fMRI at high fields [1-4]. Short-term respiration effects result from B0 modulation due to bulk susceptibility changes from thoracic organ movement and gas volume as well as head motion [3-5]. Recently low-frequency fluctuations in the depth and the rate of respiration have been...

Soil respiration is one of the major carbon (C) fluxes between terrestrial ecosystems and the atmosphere and plays an important role in regulating the responses of ecosystem and global C cycling to natural and anthropogenic perturbations. A field experiment was conducted between April 2005 and October 2006 in a semiarid grassland in northern China to examine effects of topography, fire, nitroge...

We studied the effect of two types of mesoporous silica nanoparticles, MCM-41 and SBA-15, on mitochondrial O 2 consumption (respiration) in HL-60 (myeloid) cells, Jurkat (lymphoid) cells, and isolated mitochondria. SBA-15 inhibited cellular respiration at 25-500 microg/mL; the inhibition was concentration-dependent and time-dependent. The cellular ATP profile paralleled that of respiration. MCM...

Bioirrigation or the transport of fluids into the sediment matrix due to the activities of organisms such as bloodworms (larvae of Diptera, Chironomidae), has substantial impacts on sediment respiration in lakes. However, previous quantifications of bioirrigation impacts of Chironomidae have been limited by technical challenges such as the difficulty to separate faunal and bacterial respiration...

Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature (MAT), but the rate of this cross-ecosystem i...

This study examined the effect of tree species identity and diversity on soil respiration in a 3-year-old tropical tree biodiversity plantation in Central Panamá. We hypothesized that tree pairs in mixed-species plots would have higher soil respiration rates than those in monoculture plots as a result of increased primary productivity and complementarity leading to greater root and microbial bi...

In the short-term heterotrophic soil respiration is strongly and positively related to temperature. In the long-term, its response to temperature is uncertain. One reason for this is because in field experiments increases in respiration due to warming are relatively short-lived. The explanations proposed for this ephemeral response include depletion of fast-cycling, soil carbon pools and therma...