Search results for " respiration"
showing 10 items of 208 documents
Effects of pentachlorophenol in forest soil: a microcosm experiment for testing ecosystem responses to anthropogenic stress
1996
Changes in the structure and function of a soil decomposer community and growth of birch (Betula pendula) due to chemical contamination were studied in laboratory microcosms. Sodium pentachlorophenate (PCP) was added to the humus layer of a simulated forest soil at three nominal concentrations (0, 50 and 500 mg kg-1 dry mass). After two growing periods (48 weeks), there were more small soft-bodied mites, but less collembolans and microbial biomass, in the higher PCP concentration treatment than in the other treatments. Number of enchytraeids were significantly reduced and fungal-feeding nematodes became extinct in the soil with the higher PCP concentration. Soil respiration did not change d…
Cover Crop Impact on Soil Organic Carbon, Nitrogen Dynamics and Microbial Diversity in a Mediterranean Semiarid Vineyard
2020
Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season
Responses to increases in temperature of heterotrophic micro-organisms in soils from the maritime Antarctic
2015
Understanding relationships between environmental changes and soil microbial respiration is critical for predicting changes in soil organic carbon (SOC) fluxes and content. The maritime Antarctic is experiencing one of the fastest rates of warming in the world and is therefore a key location to examine the effect of temperature on SOC mineralization by the respiration of soil micro-organisms. However, depletion of the labile substrates at higher temperatures relative to the total SOC and greater temperature sensitivity of recalcitrant components of the SOC confound simple interpretations of the effects of warming. We have addressed these issues by testing the hypothesis that respiration by …
Andamento stagionale del flusso di emissione di CO2 dal suolo in risposta al contenuto di umidità all'interno di un agroecosistema mediterraneo
2014
Total soil respiration as the sum of two biotic component, autotrophic and heterotrophic respiration, is influenced by various environmental factor, in particular soil temperature and soil moisture. In arid and semi arid regions, soil moisture is a major driver of soil respiration during periods of drought stress. Hence, the aim of this work was to evaluate the effect of soil moisture on soil CO2 efflux. Measurements were made every two weeks between January 2008 and June 2010 using a portable soil respiration instrument fitted with a soil respiration chamber (IRGA) CIRAS 1 (PP Systems, Hitchin, UK).The Simultaneously with soil respiration measurements, soil temperature (T) and soil volumetri…
Impact of Innovative Agricultural Practices of Carbon Sequestration on Soil Microbial Community.
2011
This chapter deals with the impact on soil microbiology of innovative management techniques for enhancing carbon sequestration. With in the MESCOSAGR project, the effect of different field treatments was investigated at three experimental sites differing in pedo-climatic characteristics. Several microbiological parameters were evaluated to describe the composition of soil microbial communities involved in the carbon cycle, as well as to assess microbial biomass and activity. Results indicated that both compost and catalyst amendments to field soils under maize or wheat affected microbial dynamics and activities, though with out being harmful to microbial communities.
Responses of methane oxidation to temperature and water content in cover soil of a boreal landfill
2007
Abstract Methane oxidation in a cover soil of a landfill located in a boreal climate was studied at temperatures ranging from 1–19 °C and with water content of 7–34% of dry weight (dw), corresponding to 17–81% of water-holding capacity (WHC) in order to better understand the factors regulating CH 4 oxidation at low temperatures. CH 4 consumption was detected at all the temperatures studied (1–19 °C) and an increase in CH 4 consumption rate in consecutive incubations was obtained even at 1 °C, indicating activation or increase in enzymes and/or microorganisms responsible for CH 4 oxidation. CH 4 consumption was reduced with low water content (17%WHC) at all temperatures. The response of CH 4…
Immediate effects of the respiratory stimulation on ventilation parameters in ischemic stroke survivors: A randomized interventional study (CONSORT).
2019
Background: Post-stroke brain damage, which affects the central control of respiration, leads to various respiratory disorders. They can be caused by the weakening of the respiratory muscles and chest movements, which can indirectly contribute to an impairment of the ventilation function. The aim of the study is an objective assessment of the effect of a single-session intervention of respiratory stimulation through Proprioceptive Neuromuscular Facilitation (PNF) on chosen respiratory parameters and the following comparison of these changes with a group in which positioning was used (intra- and intergroup comparison). Methods: This was a randomized interventional study evaluating the respir…
Quantification of Lung Volume at Different Tidal Volumes and Positive End-Expiratory Pressures in a Porcine Model by Using Retrospective Respiratory …
2008
PURPOSE: This feasibility study in healthy animals should prove the concept that it is possible to quantitatively assess the effects of different ventilatory settings on the lung parenchyma during ongoing ventilation in respiratory gated 4-dimensional (D)-computed tomography (CT). For this purpose, the influence of different tidal volumes and positive end-expiratory pressure (PEEP) on quantitative assessment of lung volumes (LVs) and lung compartments was analyzed. METHODS: Five anesthetized and ventilated (20 breaths/min, inspiratory/expiratory ratio of 1:2) healthy pigs underwent 16-row multidetector CT with retrospective respiratory gating using a noncontact charge-coupled device camera …
Activity of bulbar respiratory modulated neurons and restart of respiration after hypocapnic apnea in rabbits
1980
The activity of respiratory modulated neurons at the end of the apneic pause and during restart of respiration and the diaphragmatic mass activity were examined and both were compared to quiet respiration. Thresholds of mutual inhibition of neurons are unevenly distributed within various phase types of neurons.
Concurrent fast and slow synchronized efferent phrenic activities in time and frequency domain.
1990
Abstract In urethane-anesthetized or decerebrated vagotomized rabbits efferent multifiber activity of the phrenic nerve was investigated for synchronized activities both in time and frequency domains. When respiratory drive was steadily increased by either an elevation of end-tidal CO2 concentration or i.v. administration of 4-aminopyridine, medium-frequency oscillations (MFO) first increased, then decreased and finally became absent. The power of high-frequency oscillations (HFO) steadily rose with increasing respiratory drive. In contrast to HFO which revealed a unimodal spectral peak of mostly small bandwidth, the MFO spectrum in most cases consisted of a broad complex. This complex in s…