Respiration Index Research Articles

Using the Index of Abdominal Respiration to Evaluate the Breathing State of Regiment Qigong

Using the Index of Abdominal Respiration to Evaluate the Breathing State of Regiment Qigong

Zooplankton biomass and indices of feeding and metabolism in island-generated eddies around Gran Canaria

Zooplankton biomass and indices of grazing (gut fluorescence), respiration (electron transfer system, ETS), ammonia excretion (glutamate dehydrogenase, GDH) and growth (aspartate transcarbamylase, ATC) were studied around the island of Gran Canaria (Canary Islands) during the so-called “late winter bloom”. Four size classes (100–200, 200–500, 500–1000 and >1000 μm) were studied to assess the contribution of each size fraction to the mesoscale plankton distribution around the island. Cyclonic and anticyclonic eddies were observed downstream the island transporting and entraining water rich in chlorophyll. Zooplankton biomass showed a high variability around the island but it was dramatically lower in the core of the cyclonic eddy induced by the island, probably due to the divergent effect produced by the physical structure. A filament of relatively cold-water was also found reaching the island from the upwelling area off northwest Africa. High zooplankton biomass was observed in association with the filament water and in the vicinity of the anticyclonic eddy shed by the island. Specific gut content showed higher values in the boundaries of the cyclonic structures, while ETS and GDH activities where higher windward of the island, in both the cyclonic and anticyclonic eddies depending on the size fraction considered. With the restrictions of using those indices, control of primary production by grazing was 11–22% and up to 41% of the calculated ingestion from the indices of metabolism and growth could be supported by nonpigmented food. Calculated excretion rates could support about 8% of primary production. The low impact of zooplankton on autotrophic production, the low values of the index of growth and the distribution of biomass in relation to the presence of eddies downstream of Gran Canaria suggest that accumulation was the causative mechanism for the presence of high zooplankton biomass leeward of the island.

Determination of Biological Stability by Oxygen Uptake on Municipal Solid Waste and Derived Products

A new scientific apparatus and method are proposed for determining biological stability by oxygen uptake (respiration index, RI), on municipal solid waste (MSW) and derived products. For measuring the RI, a dynamic approach (with continuous aeration) was demonstrated to be more effective than the static approach (without aeration). The validity of the method was tested by comparing carbon losses calculated using both respirometric (carbon lossesresp) and analytical data (carbon lossesanal) during four trials performed on MSW and products derived from it. Carbon losses (expressed as g kg−1Ci, in which Ci represents initial carbon content) were: 219.0 and 248.0, 67.9 and 57.1, 39.6 and 36.4, and 250.7 and 280.3, using respirometric and analytical data alternately for Trials 1,2,3, and 4. The comparison between respirometric data using continuous or no aeration showed, for the latter, an underestimation of RI of between 70% and 90% that was more evident for unstable biomass leading to more similar values when stabilization occurred. The scientific apparatus proposed made it possible to measure oxygen uptake under autothermal conditions and avoid problems connected with the use of a preset temperature, biomass temperature being a consequence of the microbial activity, as is also suggested by the significant linear regression of T versus RI (R2 = 0.84, 0.73, 0.82, and 0.90 for the four trials, respectively). The methods proposed could be used with advantage in the future for biological stability measurements, above all for heterogeneous material such as MSW and its products, thus obtaining respirometric data that better reflect what happens during an aerobic process.

Macrocompartmentation of total creatine in cardiomyocytes revisited.

Distribution of total creatine (free creatine + phosphocreatine) between two subcellular macrocompartments--mitochondrial matrix space and cytoplasm--in heart and skeletal muscle cells was reinvestigated by using a permeabilized cell technique. Isolated cardiomyocytes were treated with saponin (50 microg/ml for 30 min or 600 microg/ml for 1 min) to open the outer cellular membrane and release the metabolites from cytoplasm (cytoplasmic fraction, CF). All mitochondrial population in permeabilized cells remained intact: the outer membrane was impermeable for exogenous cytochrome c, the acceptor control index of respiration exceeded 10, the mitochondrial creatine kinase reaction was fully coupled to the adenine nucleotide translocator. Metabolites were released from mitochondrial fraction (MF) by 2-5% Triton X100. Total cellular pool of free creatine + phosphocreatine (69.6 +/- 2.1 nmoles per mg of protein) was found exclusively in CF and was practically absent in MF. When fibers were prepared from perfused rat hearts, cellular distribution of creatine was not dependent on functional state of the heart and only slightly modified by ischemia. It is concluded that there is no stable pool of creatine or phosphocreatine in the mitochondrial matrix in the intact muscle cells, and the total creatine pool is localized in only one macrocompartment--cytoplasm.

00/02009 The U.S. wind market is back

The Landfill Directive (1999/31/EC) forces European States to reduce the amount of biodegradable municipal waste landfilled to 35% of 1995 levels. Mechanical-Biological Treatment (MBT) plants are the main alternative to waste incineration and landfilling. In this work, the waste treatment efficiency of six full-scale MBT facilities has been analysed using respiration indices (Dynamic Respiration Index and Cumulative Oxygen Consumption) to monitor plant performance. MBTs relying on anaerobic digestion plus composting achieved a high grade of stability on final compost (0.24 ± 0.09 mg O2 g−1 DM h−1 and 20 ± 9 mg O2 g−1 DM for dynamic respiration and cumulative consumption, respectively). On the contrary, MBTs relying only on composting showed a poor performance (1.3 ± 0.2 mg O2 g−1 DM h−1 and 104 ± 18 mg O2 g−1 DM for dynamic respiration and cumulative consumption, respectively). These results highlight the usefulness of respirometric balances to assess the performance of MBT full-scale plants.

Blunted respiratory responses to hypoxia in mutant mice deficient in nitric oxide synthase-3.

In the present study, the role of nitric oxide (NO) generated by endothelial nitric oxide synthase (NOS-3) in the control of respiration during hypoxia and hypercapnia was assessed using mutant mice deficient in NOS-3. Experiments were performed on awake and anesthetized mutant and wild-type (WT) control mice. Respiratory responses to 100, 21, and 12% O(2) and 3 and 5% CO(2)-balance O(2) were analyzed. In awake animals, respiration was monitored by body plethysmography along with O(2) consumption (VO(2)) and CO(2) production (VCO(2)). In anesthetized, spontaneously breathing mice, integrated efferent phrenic nerve activity was monitored as an index of neural respiration along with arterial blood pressure and blood gases. Under both experimental conditions, WT mice responded with greater increases in respiration during 12% O(2) than mutant mice. Respiratory responses to hyperoxic hypercapnia were comparable between both groups of mice. Arterial blood gases, changes in blood pressure, VO(2), and VCO(2) during hypoxia were comparable between both groups of mice. Respiratory responses to cyanide and brief hyperoxia were attenuated in mutant compared with WT mice, indicating reduced peripheral chemoreceptor sensitivity. cGMP levels in the brain stem during 12% O(2), taken as an index of NO production, were greater in mutant compared with WT mice. These observations demonstrate that NOS-3 mutant mice exhibit selective blunting of the respiratory responses to hypoxia but not to hypercapnia, which in part is due to reduced peripheral chemosensitivity. These results support the idea that NO generated by NOS-3 is an important physiological modulator of respiration during hypoxia.

Factors Affecting Metabolism of Commercial Channel Catfish Ponds as Indicated by Continuous Dissolved Oxygen Measurement1

AbstractContinuous dissolved oxygen (DO) measurements were analyzed to evaluate the rates of pond metabolic processes related to productivity and respiration in three commercial catfish ponds in northwest Mississippi. Multiple regression models were constructed to assess the relative importance of various forcing functions on indices of net primary productivity (NPP) and whole pond respiration (WPR), duration of automated aeration, and DO concentration below various threshold values. Water temperature, solar radiation, wind run, cumulative feed, and lagged values of these parameters were considered as forcing functions. Generally, NPP and WPR were most strongly affected by water temperature and only weakly related to solar radiation. The duration of nightly aeration was also strongly related to water temperature, although 10‐d cumulative feed was an important predictor in one pond. The best predictors of duration of DO below certain threshold values were NPP, WPR and wind run, the importance of which varied depending upon the pond and the threshold value considered. Change in feeding rate from one day to the next was inversely related to feeding rate on the previous day. The results of this analysis suggest that NPP and WPR rates, and the duration of required nightly aeration in commercial catfish ponds are controlled by factors not amenable to practical management control.

Estimating CO2 exchange at two sites in Arctic tundra ecosystems during the growing season using a spectral vegetation index

Measurements of carbon fluxes in Arctic tundra landscapes are generally obtained through intensive field work and involve the use of chamber and/or micrometeorological tower techniques. However, findings in a variety of nonArctic ecosystems have demonstrated the potential of remote sensing-based techniques (particularly spectral vegetation indices) to provide estimates of CO2 exchange in a more timely and efficient manner. As the firststep towards modelling Arctic regional and circumpolar fluxes of CO2 using remotely sensed data, we investigated the relationships between plot-level fluxes of CO2 and a vegetation spectral reflectance index derived from hand-held radiometric data at two sites. These relationships were evaluated for variations in vegetation cover type and environmental factors using data collected during the short Arctic growing season. Overall, this study demonstrated a relationship between the Normalized Difference Vegetation Index (NDVI) and measurements of mean site gross photosynthesis and ecosystem respiration at two sites in Arctic tundra ecosystems on the North Slope of Alaska.

Altered respiratory responses to hypoxia in mutant mice deficient in neuronal nitric oxide synthase.

1. The role of endogenous nitric oxide (NO) generated by neuronal nitric oxide synthase (NOS-1) in the control of respiration during hypoxia and hypercapnia was assessed using mutant mice deficient in NOS-1. 2. Experiments were performed on awake and anaesthetized mutant and wild-type control mice. Respiratory responses to varying levels of inspired oxygen (100, 21 and 12% O2) and carbon dioxide (3 and 5% CO2 balanced oxygen) were analysed. In awake animals, respiration was monitored by body plethysmograph along with oxygen consumption (VO2), CO2 production (VCO2) and body temperature. In anaesthetized, spontaneously breathing mice, integrated efferent phrenic nerve activity was monitored as an index of neural respiration along with arterial blood pressure and blood gases. Cyclic 3',5'-guanosine monophosphate (cGMP) levels in the brainstem were analysed by radioimmunoassay as an index of nitric oxide generation. 3. Unanaesthetized mutant mice exhibited greater respiratory responses during 21 and 12% O2 than the wild-type controls. Respiratory responses were associated with significant decreases in oxygen consumption in both groups of mice, and the magnitude of change was greater in mutant than wild-type mice. Changes in CO2 production and body temperature, however, were comparable between both groups of mice. 4. Similar augmentation of respiratory responses during hypoxia was also observed in anaesthetized mutant mice. In addition, five of the fourteen mutant mice displayed periodic oscillations in respiration (brief episodes of increases in respiratory rate and tidal phrenic nerve activity) while breathing 21 and 12% O2, but not during 100% O2. The time interval between the episodes decreased by reducing inspired oxygen from 21 to 12% O2. 5. Changes in arterial blood pressure and arterial blood gases were comparable at any given level of inspired oxygen between both groups of mice, indicating that changes in these variables do not account for the differences in the response to hypoxia. 6. Respiratory responses to brief hyperoxia (Dejours test) and to cyanide, a potent chemoreceptor stimulant, were more pronounced in mutant mice, suggesting augmented peripheral chemoreceptor sensitivity. 7. cGMP levels were elevated in the brainstem during 21 and 12% O2 in wild-type but not in mutant mice, indicating decreased formation of nitric oxide in mutant mice. 8. The magnitude of respiratory responses to hypercapnia (3 and 5% CO2 balanced oxygen) was comparable in both groups of mice in the awake and anaesthetized conditions. 9. These observations suggest that the hypoxic responses were selectively augmented in mutant mice deficient in NOS-1. Peripheral as well as central mechanisms contributed to the altered responses to hypoxia. These results support the idea that nitric oxide generated by NOS-1 is an important physiological modulator of respiration during hypoxia.

Temporal variation of C and N mineralization, microbial biomass and extractable organic pools in soil after oilseed rape straw incorporation in the field

The temporal variation of soil microbial biomass C and N, extractable organic C and N, mineral N and soil-surface CO 2 flux in situ in two arable soils (a sandy loam and a coarse sandy soil) was examined periodically for a full year after field incorporation of 0, 4 or 8 t dry mass ha −1 of oilseed rape straw in late summer. Both unlabelled and 15N-labelled straw were applied. Soil-surface CO 2 flux, used as an index of soil respiration, was up to 2-fold higher in the straw-amended treatments than in the unamended treatment at both sites during the first 6–8 wk, but the general temporal pattern was mainly controlled by soil temperature and soil water content. Microbial biomass C and N increased very rapidly after the straw amendments and the 31–49% difference from the unamended treatment persisted throughout the winter. Temporal variations in soil microbial biomass C and N were only within ±13–22% of the mean at both sites and in all straw treatments over the 1 y period. Microbial biomass C-to-N ratios were not significantly different between straw treatments and were relatively constant over time. Extractable organic C and N were slightly higher in the straw-amended treatments and were higher in spring and summer than in autumn and winter. More than 90% of the added straw N could be accounted for initially and there was no loss of straw N over the winter period, in spite of a winter rainfall that was twice the 25 y average. Between 52 and 80% of the initial increase in microbial biomass N was derived from the straw N, with up to 27% of the straw N being incorporated into the microbial biomass. Rapid immobilization of soil mineral N occurred simultaneously and the sum of this and the straw-derived microbial biomass N on day 7 exceeded the total increase in microbial biomass N, indicating a very rapid turnover of microbial biomass in the first few days. Significant differences in microbial biomass C and N between the straw treatments were still found after nearly 1 y and the decay constant of straw-derived microbial biomass N was estimated to be ca. 0.26 y −1.

Augmented sympathetic tone alters muscle metabolism with exercise: lack of evidence for functional sympatholysis.

It is unclear whether sympathetic tone opposes dilator influences in exercising skeletal muscle. We examined high levels of sympathetic tone, evoked by lower body negative pressure (LBNP, -60 mmHg) on intramuscular pH and phosphocreatine (PCr) levels (31P-nuclear magnetic resonance spectroscopy) during graded rhythmic handgrip (30 contractions/min; approximately 17, 34, 52 and 69% maximal voluntary contraction). Exercise was performed with LBNP and without LBNP (Control). At the end of exercise, LBNP caused lower levels of muscle pH (6.59 +/- 0.09) compared with Control (6.78 +/- 0.05; P < 0.05). PCr recovery, an index of mitochondrial respiration, was less during the recovery phase of the LBNP trial. Exercise mean arterial pressure was not altered by LBNP. The protocols were repeated with measurements of forearm blood flow velocity and deep venous samples (active forearm) of hemoglobin (Hb) saturation, pH, and lactate. With LBNP, mean blood velocity was reduced at rest, during exercise, and during recovery compared with Control (P < 0.05). Also, venous Hb saturation and pH levels during exercise and recovery were lower with LBNP and lactate was higher compared with Control (P < 0.05). We conclude that LBNP enhanced sympathetic tone and reduced oxygen transport. At high workloads, there was a greater reliance on nonoxidative metabolism. In other words, sympatholysis did not occur.

Soil surface CO 2 flux as an index of soil respiration in situ: A comparison of two chamber methods

Predictions of global climate change have recently focused attention on soils as major sources and sinks for atmospheric CO 2, and various methodologies exist for measuring soil surface CO 2 flux. A static (passive CO 2 absorption in an alkali trap over 24 h) and a dynamic (portable infra-red CO 2 gas analyzer over 1–2 min) chamber method were compared. Both methods were used for 100 different site × treatment × time combinations in temperate arable, forest and pasture ecosystems. Soil surface CO 2 flux estimates covered a wide range from 0 to ca. 300 mg CO 2C m −2 h −1 by the static method and from 0 to ca. 2500 mg CO 2C m −2 h −1 by the dynamic method. The relationship between results from the two methods was highly non-linear, and was best explained by an exponential equation. When compared to the dynamic method, the static method gave on average 12% higher flux rates below 100 mg CO 2C m −2 h −1, but much lower flux rates above 100 mg CO 2C m −2 h −1. Spatial variability was large for both methods, necessitating a large number of replicates for reliable field data, with typical coefficients of variation being in the range 10–60%, usually higher with the dynamic than the static method. Diurnal variability in soil surface CO 2 flux was partly correlated with soil temperature, whereas day-to-day variability was more unpredictable. However, use of a mechanistic simulation model of CO 2 transport in soil, SOILCO2, showed that very large day-to-day changes in soil surface CO 2 flux can result from rainfall events causing relatively small changes in soil water content above field capacity (ca. −10 kPa), even if CO 2 production rates remained relatively unaffected.

Factors affecting the respiration/ETS ratio in marine zooplankton

Factors affecting the respiration/ETS ratio in marine zooplankton

Enzymatic indices of respiration and ammonia excretion: relationships to body size and food levels

Enzymatic indices of respiration and ammonia excretion: relationships to body size and food levels

中枢性鎮痛薬Ｅｐｔａｚｏｃｉｎｅのマウス，ラットにおける虚血性脳障害に対する保護効果

The cerebral protective effect of eptazocine, an opioid mu-antagonist-kappa-agonist, was investigated using mice and rats subjected to ischemia. 1) Decapitation or concussive head injury (20 g, 30 cm)-induced ischemia in mice: Eptazocine (3,10 mg/kg) prolonged the gasping duration or the survival time in a dose-dependent manner. 2) Ischemic brain edema induced by bilateral carotid arterial occlusion (BLCO) in rats: Administration of eptazocine just after BLCO treatment significantly prevented the incidence of ischemic seizures, lethality and an increase in cerebral water content. 3) Acute ischemic changes in cerebral energy metabolism in mice: 2-min BLCO treatment decreased the cerebral contents of phosphocreatine and ATP, and it increased the contents of AMP and lactate, resulting in a 34% decrease in energy charge potential and an increase in lactate/pyruvate ratio. Such changes were improved by eptazocine (3, 10 mg/kg) and ethylketocyclazocine (3 mg/kg), a kappa-agonist. 4) Respiratory function in mouse brain mitochondria preparations: Eptazocine increased the State 3 respiration and respiratory control index (RCI:State 3/State 4), and it prevented a decrease in RCI induced by 3-min ischemia. These results suggest that eptazocine may improve cerebral ischemic disorders through an activation and/or protection of mitochondrial energy-producing systems.

Assessment of the respiratory metabolism in the skin from transcutaneous measurements of pO 2 and pCO 2: potential for non-invasive monitoring of response to tuberculin skin testing

A method is described for non-invasive transcutaneous (tc) measurement of tissue respiratory gas tensions in the skin on the forearm for study of delayed hypersensitivity reactions in man. Steady state values for tcpO 2 and tcpCO 2 were measured, and the skin respiratory rate (oxygen consumption) and the tissue pH were estimated from the changes in tcpO 2 and tcpCO 2 observed after interruption of the arterial circulation by cuff occlusion for 4 minutes. The extent of within-experiment and between subject variation in the steady-state measurements was not great (coefficient of variation 10%): tcpCO 2.ss (steady state) was higher in men and tcpO 2.ss was higher in women, but the extent of these sex differences was also small. Reference ranges have been established for tc measurements and calculated indices of tissue respiration in the undisturbed forearm skin of normal volunteers, against which the changes induced by tuberculin testing can be assessed. Severe changes, indicative of profound hypoxia and acidosis, are seen in intense delayed hypersensitivity reactions. Similar, but less severe changes were seen at the site of skin tests on BCG-vaccinated subjects who were ‘negative’ by conventional criteria of measurement of dermal induration and they became greatly exaggerated after successful re-vaccination. Intradermal injection of saline did not induce hypoxia or local acidosis. These new methods are very sensitive indicators of the tissue response in the DHS reaction.

Dynamics of reactions of nonspecific and somatic activation during biofeedback training

In experimental research involving the participation of 17 volunteers, we investigated the dynamics associated with indices of respiration, electromyographic activity of the hand muscles, heart rate, and electroencephalograms during training of voluntary upward and downward regulation of skin resistance and skin temperature. It was demonstrated that development of reactions of nonspecific, generalized activation appearing in the form of respiratory arrhythmia and, in a number of cases, in the form of changes in the frequency of respiration, heart rate, and an intensification of beta-activity were characteristic of the initial stages of the training. In a number of the subjects, we also noted activation of muscle groups in the areas where the sensing elements monitoring the vegetative parameters were attached. The activational reactions extinguished during reinforcement of the skill. The data obtained confirms the hypothesis that the training of adaptive biocontrol is a form of instrumental conditioning.

Electron transport system(ETS) activity as a possible index of respiration for larval walleye pollock Theragra chalcogramma.

Electron transport system (ETS) activity was measured for larvae of the walleye pollock Theragra chalcogramma, with the objective of assessing this method for estimating the respiration of fish larvae in situ. The ETS activity decreased minimally after 50 days' storage at -80°C. The ETS activity increased linearly with larval dry weight. The average dry weight-specific ETS activity of feeding stage larvae was 9.75±2.25 (S.D.) μlO2/mg•h, which was significantly higher than 5.82±0.88μlO2/mg•h for pre-feeding stage larvae. The average ratio of respiration to ETS activity was 0.47±0.16. As in laboratory raised larvae, the ETS activity in wild larvae also increased linearly with larval dry weight. The regression coefficient of laboratory raised and wild larvae were not significantly different. The average dry weight-specific ETS activity for wild larvae was 8.60±2.99μlO2/mg•h. The comparison of the ETS activity in laboratory raise and wild larvae indicates that the ETS activity method has potential to assess respiratory activity of pollock larvae in situ. Further experiments are needed to evaluate the impact of various environmental conditions to the respiration to ETS activity ratio, which is necessary to convert ETS activity data to respiration.

Involvement of ventral medullary surface in respiratory responses induced by 2,4-dinitrophenol.

We examined the contribution of the neural elements near the ventral medullary surface (VMS) to the respiratory response caused by 2,4-dinitrophenol (DNP). Two series of experiments were performed on 12 vagotomized and sinoaortic denervated cats. The first series examined the effect of focal cooling of the VMS on the respiratory response to DNP in four spontaneously breathing, anesthetized cats. When the VMS temperature was 37 degrees C, systemic administration of DNP increased minute ventilation under nearly isocapnic conditions, and focal cooling of the intermediate area of VMS to 20 degrees C attenuated the ventilatory augmentation caused by DNP. To eliminate the influence of anesthetics, a second group of experiments was performed on eight decerebrate, artificially ventilated cats while phrenic nerve activity was monitored as an index of respiration. AgNO3 (10%) was topically applied to the VMS until the respiratory response to inhaled CO2 was abolished. Apnea occurred in seven of eight cats after AgNO3, whereas in the remaining one animal, tidal phrenic activity decreased substantially. Systemic administration of DNP produced no respiratory excitation in any of the animals. On the other hand, rhythmic respiratory activity could be provoked by electrical stimulation of the mesencephalic locomotor area and carotid sinus nerve and by excitation of somatic afferents. Histological examination of the brain stem showed that the AgNO3 had penetrated no more than 350 microns from the ventral medullary surface. These results indicate superficial structures of the VMS are of potential importance in mediating the respiratory responses to hypermetabolism.

Choice of permissible limits for random measuring errors of the major respiration indexes

Choice of permissible limits for random measuring errors of the major respiration indexes