Search results for "respiration"

Ventilatory conditioning by self-stimulation in rats: A pilot study

1994

International audience; This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rewarded by an electrical stimulation of the medial forebrain bundle whenever inspiratory duration (TI) exceeded 300 ms. A bidirectional control was then used: TIs longer than 400 ms were rewarded, and then TIs shorter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but af…

Microbial communities of the kanchenjunga mountains, nepal himalaya: factors affecting abundance, culturability and activity of the high-altitude col…

2009

Metabolic Profiling of Glucose-Fed Metabolically Active Resting Zymomonas mobilis Strains

2020

Zymomonas mobilis is the most efficient bacterial ethanol producer and its physiology is potentially applicable to industrial-scale bioethanol production. However, compared to other industrially important microorganisms, the Z. mobilis metabolome and adaptation to various nutritional and genetic perturbations have been poorly characterized. For rational metabolic engineering, it is essential to understand how central metabolism and intracellular redox balance are maintained in Z. mobilis under various conditions. In this study, we applied quantitative mass spectrometry-based metabolomics to explore how glucose-fed non-growing Z. mobilis Zm6 cells metabolically adapt to change of oxygen avai…

Die Wirkung unterschiedlicher Lichtintensitäten während der Anzucht auf die CO2-Kompensationslage, die Glykolsäure-Oxidase- und Ribulosebiphosphat-Ca…

1978

Summary Sinapis alba (white mustard) plants were grown under conditions of strong (100 W · m -2 ) and weak (3 W · m -2 ) light and the effect of the light intensity during growth on the CO 2 -compensation point and the activities of glycolic acid oxidase and ribulose bisphosphate carboxylase were studied. The CO 2 -compensation concentration was determined according to two methods: firstly in a closed system with an infrared CO 2 -analyzer, and secondly according to the curve of net photosynthesis as a function of C0 2 -concentration over the range of 400 vpm CO 2 to the CO 2 -compensation point (Fig. 4). The intensity of light during growth was observed to exert an unmistakable effect on t…

Measurement of Photosynthesis and Transpiration in Spruce Trees with Various Degrees of Damage

1987

Summary In the context of a project on physiological and biochemical characterization of spruce with different degrees of damage, the C02 and H2O gas exchange of 22-year-old spruce from a location in the Hunsru.ck (West Germany) were measured in summer 1985. The measurements were carried out on shoots from 1984 and were set up as a pair comparison, i.e. the measurement data of a tree with symptoms of damage were always compared with a tree in the immediate vicinity which phenotypically showed less damage. Diurnal course measurements in the open air revealed a marked reduction of photosynthesis depending on the degree of damage of the trees. If one plots photosynthetic rate against light int…

Acetaldehyd als Indicator f�r die Regulation von Atmung und G�rung bei der aeroben Verg�rung von Glucose durch Saccharomyces cerevisiae

1971

Wahrend der aeroben Vergarung von Glucose wurde die Konzentration von Acetaldehyd im Garmedium uber den gesamten Garablauf bei mehreren Stammen von Saccharomyces cerevisiae verfolgt. Die Aldehydkonzentration weist bei Glucosekonzentrationen zwischen 5 und 20% zwei Maxima auf. Damit ist der Konzentrationsverlauf von Acetaldehyd aerob wesentlich anders als bei der anaeroben Garung, mit nur einem meist niedrigen Maximum. 10-3 M Azid hemmt die Bildung von Acetaldehyd ganz oder weitgehend. Das deutet auf die Funktion bzw. Synthese der Cytochrome, die in Gegenwart von Sauerstoff offensichtlich auch bei hohen Glucosekonzentrationen nicht vollstandig reprimiert werden. Der durch die Atmung bedingte…

Personalized intraoperative positive end-expiratory pressure: a further step in protective ventilation

2017

Upscaling leaf gas exchange measurements to the whole grapevine canopy: An update

2009

This review first revisits current knowledge about single-leaf function, viz. photosynthesis, chiefly in relation to environmental factors, that underscores the importance of multiple summer stresses. Emphasis is placed on the response different genotypes show under light and heat stress with or without soil-water shortage. Secondly, it tackles the thorny issue of extrapolating single-leaf readings to the whole-canopy level, with special reference to both methodological and physiological implications. Whole-canopy gas-exchange systems deliver and emphasise the usefulness of such an approach in achieving key research goals. One case in point is quantifying the amount and dynamics of canopy g…

The NreA Protein Functions as a Nitrate Receptor in the Staphylococcal Nitrate Regulation System

2013

Staphylococci are able to use nitrate as an alternative electron acceptor during anaerobic respiration. The regulation of energy metabolism is dependent on the presence of oxygen and nitrate. Under anaerobic conditions, staphylococci employ the nitrate regulatory element (Nre) for transcriptional activation of genes involved in reduction and transport of nitrate and nitrite. Of the three proteins that constitute the Nre system, NreB has been characterized as an oxygen sensor kinase and NreC has been characterized as its cognate response regulator. Here, we present structural and functional data that establish NreA as a new type of nitrate receptor. The structure of NreA with bound nitrate w…

The effect of iron on the biodegradation of natural dissolved organic matter

2016

Iron (Fe) may alter the biodegradation of dissolved organic matter (DOM), by interacting with (DOM), phosphorus (P) and microbes. We isolated DOM and a bacterial community from boreal lake water and examined bacterial growth on DOM in laboratory experiments. Fe was introduced either together with DOM (DOM-Fe) or into bacterial suspension, which led to the formation of insoluble Fe-precipitates on bacterial surfaces (Fe coating). In the latter case, the density of planktonic bacteria was an order of magnitude lower than that in the corresponding treatment without introduced Fe. The association of Fe with DOM decreased bacterial growth, respiration, and growth efficiency compared with DOM alo…